Diseases of the Horse's Foot
by
Harry Caulton Reeks

Part 5 out of 8




This condition is commonly the result of a severe and jagged tread with
the calkin, and takes the form of an ulcerous and excessively granulating
wound. As time goes on the granulations become hard and horny-looking, and
their fibrous tissue as hard and unyielding as tendon or cartilage.

These if treated in the early stages with repeated dressings of caustic,
or, if very exuberant, the use of the knife, usually yield to treatment. If
neglected until the condition depicted in the figure is arrived at, then
treatment, as a rule, is of no avail. Neither is treatment of any use if
any great loss of the coronary cushion has occurred.


D. FALSE QUARTER.

_Definition_.--False quarter is the term applied to that condition of the
horn of the quarter in which, owing to disease or injury of the coronet,
the wall is grown in a manner that is incomplete.

_Symptoms_.--This condition of the foot appears as a gap or shallow
indentation, narrow or wide, in the thickness of the wall, with its length
in the direction of the horn fibres. By this we do not mean that the
sensitive laminae are bared and exposed. Horn of a sort there is, and with
this the sensitive structures are covered. Running down the centre of the
incomplete horn is usually a narrow fissure marking the line of separation
in the papillary layer of the coronary cushion, which, as we shall later
see, is responsible for the malformation.

On either side of the indentation, as if wishing to aid further than
ordinarily it should in bearing the body-weight, the horn takes on an
increased growth, and stands above the level of the horn surrounding it. It
may, as perhaps it really is, be regarded as a form of hypertrophy, brought
about by the increased work that the loss of substance in the region of the
false quarter puts upon it.

So long as the sensitive structures are protected the animal remains sound.
Sometimes, however, from the effects of concussion or of the body-weight, a
fissure appears in the narrow veneer of horn that covers them. Into this,
which, of course, is but a form of sand-crack, gravel and dirt penetrate,
and so set up inflammatory changes in the keratogenous membrane. As a
result suppuration ensues, and the animal is lame.

_Causes_.--False quarter may result from any disease of the foot that
involves destruction of a portion of the coronary cushion. As we may see
from a reference to Chapter III., it is from the papillae of this body that
the horn tubules of the wall are secreted. Destruction of any portion of it
necessarily results in a corresponding loss of horn in that position. The
disease occasioning this more often than any other is perhaps quittor. It
may also result from suppurating corn, from a severe tread or overreach, or
from the effects of a slowly progressing suppurating coronitis.

_Treatment_.--A radical treatment of false quarter is not to be found. Once
destruction of the secreting layer of the coronary cushion has occurred,
the appearance of the fissure in the wall will always have to be reckoned
with. A false quarter, therefore, not only renders the horse liable to
occasional lameness, but also renders weaker that side of the hoof in which
it occurs.

The only method of treatment that can be practised, therefore, is that of
palliation. Seeing that the trouble the veterinary attendant will have to
deal with is loss of a portion of the weight-bearing surface, his attention
is immediately directed to the shoeing. As with sand-crack, so with false
quarter, the frog and the bars must be called upon to take more of the
body-weight than commonly they do with the ordinary shoe. The indication,
then, is a bar shoe. At the same time, the bearing of the wall on the shoe
on either side of the fissure should be eased by slightly paring it, and
the hypertrophied horn on the outer surface of the wall removed with the
rasp.

In cases where penetration of the sensitive structures has occurred,
complicated with the formation of pus, the same treatment as for
complicated crack is to be followed. The foot should be poulticed for
several days with hot antiseptic dressings, and thorough cleansing of the
infected parted brought about. Afterwards strong solutions of suitable
antiseptics should be applied daily until such time as the horny covering
has renewed itself. This done and the bar shoe applied, the fissure may be
plugged with any effectual stopping. Either a mixture, such as Percival's,
of pitch 2 parts, tar 1 part, and resin 1 part, melted and mixed together,
or one of the artificial hoof-horns may either be used with advantage.


E. ACCIDENTAL TEARING OFF OF THE ENTIRE HOOF.

_Causes_.--Seeing that this accident to, and consequent severe wounding of,
the keratogenous membrane nearly always occurs in but one way, it is worthy
of special mention. So far as we are able to ascertain, it is an accident
peculiar to horses continually engaged in shunting operations either in
pits or station-yards. At the moment the animal is released from the waggon
he has been pulling, and should turn to the right or the left in order
to allow it to pass him, the shoe either becomes wedged in between two
converging rails, or is trapped by the wheel of the waggon. Either the
approaching waggon with the added weight its impetus gives it then pushes
the animal suddenly away, leaving a part of his foot still fixed to the
rails, or the animal himself, feeling securely held, makes a sudden effort
to release himself, and draws his foot cleanly out of the imprisoned horny
box.

The author calls to mind a case in which entire removal of the horn of
the foot of an ox occurred through the passing over it of the wheel of
a heavily-laden cart. It is therefore quite conceivable that the same
accident might occur to the horse. As a matter of fact, we find one case on
record where one-half of the horny box was thus removed.[A]

[Footnote A: _Veterinary Record_, vol. xiii., p. 129.]

So far as we are able to gather, it is more a result of imprisonment of the
shoe than of the foot. It appears, further, to be always a result of the
animal being newly shod, and the clinches firmly secured; so much so that
it would be probable, with imperfectly secured clinches, that the animal
would draw the hoof from the clinches and the shoe rather than the foot
from its horny covering.

Therefore, as the author of one of the cases we shall afterwards relate
suggests, it should be proposed as a preventive that the shoe-nails of
animals regularly engaged in work on the metals should not be clinched in
the regulation manner, but should have their points merely screwed off, and
the nails afterwards rasped level with the wall.

These cases are particularly interesting as illustrating the rapid manner
in which a new hoof is afterwards formed, and the way in which the exposed
sensitive laminae take their share in adding to, though not forming the bulk
of, the horn of the wall.

From the cases we are able to record it will be seen that this accident
need not be looked upon as fatal, nor the injury itself beyond hope of
repair. Dependent largely upon the temperament of the animal, the amount of
pain that is caused, and the way in which the animal bears it, recovery may
be looked for. Even from the very commencement of the accident, however,
the pain may be so acute and the animal so violent with it that slaughter
becomes necessary.

_Treatment_.--This consists in applying an antiseptic and sedative dressing
to the injured parts (for example, Carbolized Oil and Tincture of Opium,
equal parts) and afterwards bandaging.

From the only data we are able to work on, it appears that this dressing
should be repeated daily, the bandage being removed, each time, the
foot well bathed in warm water, and the dressing and bandage afterwards
replaced. On first sight, it would appear that once cleansed and bandaged
the dressings might be left _in situ_ for several days. Seeing, however,
that suppuration, if once set up, would add further to the intense pain the
animal is already suffering, and considering the always constant exposure
of the foot to infection, it is perhaps wise to persist in daily changing
of the dressings.

At the same time, the general health of the animal should be attended to.
Suitable febrifuges should be administered, either in the shape of a
dose of physic, or salines and liq. ammonia. acetatis; and the pain, if
appearing unbearable, allayed by doses of choral and hypodermic injections
of morphia.

_Recorded Cases_.--1. 'A short time ago I was called to see a horse which
had had his hoof torn off in a railway "point." When I arrived at the
stable the injury had been done two hours, and the horse had been led from
the railway to a loose-box nearly half-a-mile off. On going to this box I
was surprised and horrified to find the poor animal mad with pain, rolling
and dashing himself about. When on his back he would struggle and kick the
walls with the injured foot, as though unconscious of pain. Not one moment
was he still, and as I could see that the sensitive structures were much
damaged by his violence, I obtained a gun and put him out of his pain.

'The accident happened in this way. The horse was employed in shunting
coal-waggons, and had just drawn four loaded trucks up to a point at which
they diverged to the left, and the horse, being unhooked, ought to have
turned to the right. Here, unfortunately, the near fore-foot became wedged
in between two converging railway plates, one of which formed a part of the
waggon-way, on which the trucks were running. The horse was a big animal,
and freshly shod with heavy shoes, on which a toe-piece and calkins were
used. The shoe was roughly but strongly nailed on with eight nails, the
clinches of which were all firm. This shoe was fitted wide at the heels,
and when the foot was fixed in the points (toe downwards) it protruded over
the face of the rail. When the trucks reached it they pressed it down, and,
the horse leaning forward, the hoof was drawn off like a glove. The hoof
was almost as clean inside as if taken off by maceration--only towards the
toe was a small portion of the coffin-bone and some torn laminae left inside
the hoof.

'As soon as possible after the accident, so I was told, the foot was bound
up with tow and a bandage; then a sack was cut up and placed over all, and
the horse slowly led to his loose-box. He "carried" the leg all the way,
limping along on the three sound ones. Almost immediately after reaching
the box he lay down, but only for a short time. The standing position was
not long maintained--profuse perspiration set in, and the alternations of
position became more rapid and violent, till plunging and rolling were
added to the other signs of excruciating pain. I was also told that the
groaning of the poor animal was almost constant, and at times so loud and
prolonged as to amount to a shriek.

'I have no experience of a similar case, and I should not have supposed
that this accident would have caused such acute suffering and violent
symptoms. I think I have heard of such cases making a complete recovery;
but I feel sure that, in this case, I only anticipated death by, at most, a
few hours.'[A]

[Footnote A: _Veterinary Record_, vol. iv., p. 127.]

2. 'The case I am about to give you an account of, being one of rare
occurrence, I thought would not prove uninteresting to the members of the
Veterinary Medical Association. It is an instance of complete removal of
the hoof by mechanical force.

'Our patient was a brown mare, five years old, the property of Messrs.
Crawshaw and Co., railway contractors on the Sheffield and Manchester line.

'On June 20 the mare was, as usual, working on the line, drawing one of the
waggons for the removal of soil from one place to another, and, as was the
custom, the pace is generally increased at about the distance of from sixty
to eighty yards from where the unloading takes place, in order to add to
the velocity, so that the contents of the waggons might roll down so great
a precipice. It was at this increased action, when the mare was being
removed from the waggon, that she stepped between the ends of two iron
rails, sufficiently apart to admit the foot only, when one end of the rail
inserted itself between the sole and toe of the shoe, the other at the top
and in front of the crust.

'The mare, finding herself fixed, endeavoured to disengage herself, and, in
doing so, got in front of the waggon, which, coming at a great pace, forced
her down into the pit, leaving behind the off fore-hoof, which was only
removed from its situation between the two rails by a large hammer, it
being so firmly wedged in. The shoe and hoof were bent in a very peculiar
manner, as the accompanying cuts will show, the inside heel being
completely raised from above the level of the frog, not one of the nails
being unclenched, or in the slightest degree having given way to so large
an amount of force imposed upon them, although the toe of the shoe was
raised from the sole by the rail being immediately under it (see Fig. 114).
The mare had been shod the day before, and, having a good sound foot, the
shoe was firmly put on.

'Being a mile from home, she was with some difficulty made to travel that
distance. On her arrival, my preceptor, Mr. Taylor, was immediately sent
for, who found her, as I have before stated, with the off fore-foot
hoofless.

'Proceeding to examine the foot, he ascertained that it had bled
considerably, which, however, was stopped by bandages to the foot and a
ligature round the coronet. The laminae on one side and a small portion of
the sensitive sole, though not to any great extent, were lacerated. The
coffin-bone was not at all injured. The bleeding having nearly ceased,
she was put into slings, the foot carefully washed with warm water, and
immediately bound up with pledgets of tow saturated with the simple
tincture of myrrh and tincture of opium, of each equal parts.

[Illustration: FIG. 114.--HOOF TORN FROM THE FOOT BY ACCIDENT.]

'The dressing was ordered to be allowed to remain on all night, and on the
following morning to be removed. The foot was then bathed, as before,
in warm water, and the application of the tinctures repeated night and
morning. The medicine internally given was castor oil, with tinct. opium,
and this, in a diminished dose, was ordered the next morning. Blood was
also abstracted from the jugular vein, to the amount of 6 quarts, so as
to allay the inflammatory fever set up. The food consisted of bran and
linseed, with small portions of hay and water. The mare being in a highly
excited state, and suffering such severe pain, the opinion Mr. Taylor gave
was that, should she get over the first four days (which appeared quite
uncertain), he had no doubt of her ultimately getting well, and also that
she would have a perfect hoof formed. It was now left for the owners'
consideration, whether they thought the mare worth her keep till such took
place, the time mentioned by Mr. Taylor being four or five months. She was
seen again the fourth day after the accident, and was then found to be
perfectly tranquil and feeding well; her pulse, which at the first visit
could not be counted, was now not more than 65 beats in the minute. On
removing the dressings, the foot presented a very favourable appearance,
the treatment therefore varied only in the application of a linseed-meal
poultice over the former dressings of tinctures of opium and myrrh,
confining the whole in a soft leather boot. Diet as before, in addition to
which give a few oats. Should the bowels become constipated, repeat the
castor oil without the opium.

'_June_ 28.--The animal was again seen, and appeared to be going on very
favourably. The poultices were directed to be discontinued, and the parts
dressed every other day with sol. sulph. cupri, as the granulations were
getting rather luxuriant.

'_July_ 6.--To-day she was found to have gone on so well, having two days
before been removed from the slings, that it was thought justifiable to
turn her out, protecting the foot with a boot, and ordering the dressings
to be repeated.

'_July_ 23.--She was seen by me in the field, where I had the boot removed,
and so much had she improved, that not less than 2 inches of crust,
proceeding from the coronary ring, had been formed, and the foot looked
remarkably healthy.

'It will be seen that the accident occurred on June 20, a fortnight after
which time I observed the horny crust to be forming from the coronet,
and the insensitive laminae at the same time, in which on every visit an
increase of growth was perceptible, and it soon attained a thickness
exceeding that of the other hoof, but which at the same time presented a
more upright appearance. It was not until three weeks after our first visit
that any formation of new sole or frog was to be seen. Of the two the sole
was the first, being secreted by the sensitive sole, the growth proceeding
from the heels. In like manner the insensitive frog was being produced by
the sensitive.

[Illustration: FIG. 115.--HOOF TORN FROM THE FOOT BY ACCIDENT.]

'During the last week in October the mare, having her foot protected with a
bar shoe plated at the bottom, and so formed as to open without necessity
of removing the shoe, in order to facilitate the applications of the
tinctures, was put to light work, which has since been gradually increased,
and she now performs her usual labour equal to any other horse.

'The growth of the wall or crust and insensitive laminae is not yet quite
complete, nor is the sole, there being wanting about an inch of the horny
substance of it, the entire completion of which I should rather doubt, as I
mentioned in my former communication that the sensitive laminae and a small
portion of the sole were lacerated, and it is in these parts that the
imperfections exist.

'The yet imperfectly-formed wall not admitting of the insertion of nails
all around it, the shoe is held on partly by nails and partly by a strap
attached to it bound round the coronet.'[A]

[Footnote A: _Veterinary Record_, vol. iv., p. 182 (B. Cartledge).]

3. 'This case is related by Mr. A. Rogerson, F.R.C.V.S. It occurred to an
animal regularly engaged in shunting, and happened through the corner of
the shoe becoming "trapped" between a line of metal and the wheel of
a truck. It is particularly interesting on account of the photograph
accompanying it, and which we here reproduce in Fig. 115.

'The photograph shows plainly the manner in which the holding of the
"clinches" on the left side of the hoof has resulted in drawing it off
from the foot. Had these clinches, as Mr. Rogerson suggests, been left
unfastened, then the accident in all probability would not have occurred.
The animal was destroyed.'[A]

[Footnote A: _Ibid_., vol. xiii., p. 2.]



CHAPTER IX

INFLAMMATORY AFFECTIONS OF THE KERATOGENOUS APPARATUS


A. ACUTE.

ACUTE LAMINITIS.

_Definition_.--The term 'laminitis' is used to indicate a spontaneous and
diffuse inflammation of the whole of the sensitive structures of the foot,
more particularly the sensitive laminae. Usually it occurs in the two front
feet, often in all four, and occasionally in the hind alone.

_Causes_.--In dealing with the causes of laminitis, we will first dispose
of those coming under the heading of _traumatic_. Correctly speaking,
however, lesions of the laminae thus occurring do not present the same
symptoms, nor run an identical course with the disease we now purpose
describing, and for which we would prefer to entirely reserve the term
'laminitis.' The fact, however, that traumatic causes are detailed in other
works on the same subject compels us to give them mention here.

Strictly traumatic causes giving rise to a limited inflammation of the
sensitive laminae are violent blows upon the foot, either purely accidental,
or self-inflicted by violent kicking.

A similar limited laminitis is to be found in the conditions we have
described under 'Nail-bound and Punctured Foot.' It is met with also in
the injuries resulting from tread and overreach, and in the tissue-changes
accompanying corn.

The tenderness following upon excessive hammering in the forge, or of too
long an application of the shoe in hot-fitting has also been described as
laminitis.

With either of the conditions we have mentioned, it goes without saying
that there is either a simple congestion or an actual inflammation,
localized or general, of the laminae of the injured foot. In neither case,
however, can the resulting mischief be closely compared with the lesions
attending an attack of laminitis proper, a disease which appears to have an
almost specific cause, and to run a course peculiarly its own.

The specific cause we have indicated as existing can, in the present state
of our knowledge, be only vaguely described as a poisoned state of the
blood-stream. This, as clinical evidence teaches us, may result from a
variety of causes.

Among these, by far the most common is that state of the circulation
induced by excessive feeding with too stimulating or too irritating a diet.
In any case, where the use of old oats as a staple diet is departed from,
and where the quantity and manner of using the substitute is left to the
discretion of careless or unskilled attendants, trouble is likely to ensue.
The food more prone, perhaps, than any other to bring about an attack is
wheat improperly prepared--that is, uncooked or unground. So much so is
this the case that one full meal of this provender to an animal unused to
it is sufficient to lead to a train of symptoms often ending fatally.

Beans, peas, barley, rye, new maize, or even new oats, are all liable, if
carelessly used, to have the same effect.

It is the laminitis following feeding on new oats that has caused us to
apply to the food the adjective 'irritating.' Here, more often than not,
the peristaltic action of the bowels is found to be abnormally in evidence,
and the excessive use of the diet is always accompanied by a more or less
fluid discharge of the intestinal contents.

In addition to the foods we have mentioned, many others might be
enumerated, more especially the numerous 'made-up' feeding materials now
on the market. Many are composed of substances that may be regarded as
absolutely opposed to the correct feeding of a horse, and their use can
only be followed by this and other evil results.

Another most fruitful cause of laminitis is a severe and continued
inflammatory condition of the system elsewhere. It is the laminitis known
to veterinary surgeons as 'metastatic,' and perhaps the two most notable
examples of it are the laminitis following a prolonged attack of pneumonia,
and the 'Parturient Laminitis' occurring as a concomitant of septic
metritis.

Parturient laminitis it is that offers us the most striking illustration of
the truth that a poisoned state of the blood-stream is a sure factor in the
causation of an attack. From the direct evidence of our senses (namely,
manual exploration of the infected womb, and the stench of the exuding
discharge) we know that we have in the interior of the womb matter in a
state of putrescence. From the experience of previous post-mortems we
know, further, that the putrescent matter thus originating often gains the
blood-stream, and forms foci of septic lesions elsewhere--liver or lung.
When, therefore, during an attack of septic metritis a condition of
laminitis supervenes, we are justified in attributing it to the escape of
septic matter from the already infected uterus.

In the same category of laminitis from metastasis may also be placed the
laminitis occurring as a result of an overdose of aloes. The enteritis thus
set up is often followed by laminitis, and that of a serious type.

Prolonged and excessive work upon a hard road is also apt to induce an
attack. When this occurs it in many cases resolves itself into a case of
cruelty. (See reported case, No. 1, p. 279.)

Laminitis from this cause was frequent among coach and carriage horses in
the pre-railroad period, and resulted from attempting to obtain from the
animal a faster pace and a greater number of miles than he was physically
capable of giving.

In our day, however, it is more often a result of gross feeding, combined
with only that amount of work which the horse, if ordinarily fed, would
be easily able to perform. An excellent example of this is the laminitis
occurring in the Shire stallion when commencing his rounds of service in
the spring and early summer. At this season these animals are constantly
supplied with a more than sufficient supply of a highly stimulating and
nutritious diet. In this case the blood is already in that state in which
it is predisposed to the disease. Add to this the unwonted exercise--for
during all the winter the animals are idle--and congestion of the venous
apparatus of the extremities is not to be wondered at.

Passing from these, the more common, we may consider other and less
frequent causes of the disease. Congestion of the laminal blood-vessels and
consequent laminitis occurs when animals are made to maintain a standing
position for prolonged periods, as, for instance, when making sea voyages.
A long and painful disease of one foot, necessitating the whole of the
weight being borne by the other, ends often in laminitis of the second
member. It may thus occur as a sequel to quittor, complicated sand-crack,
suppurating corn, and punctured wounds of the feet.

Laminitis has also been known to occur as a result of septic infection of
the blood-stream consequent on the operation of castration. (See recorded
case, No. 2, p. 281.)

A sudden lowering of the surface circulation at a time when the animal is
excessively perspiring is also said to favour an attack, as also is the
giving to drink of cold water to an animal just in from a long and tiring
journey. Also, according to Zundel, 'the influence of the season cannot be
denied, and it is during the summer months that laminitis is more frequent,
while it is rare in winter, as well as in the spring and autumn.'

Further, laminitis has been described as occurring when the animal is at
grass, and when all causes--at any rate, active ones--have appeared to be
absent. (See reported case, No. 3, p. 282.)

Regarding heredity, we may safely say that, as a cause of laminitis, it may
be almost totally disregarded. That a bad form of foot, either a flat-foot
or a foot with heels contracted, and already thus affected with a mild type
of inflammation, did not offer a certain predisposition, we should not like
to assert. There must, however, be an exciting cause--namely, a poisoned
condition of the blood-stream. This latter cannot, of course, be in any way
regarded as hereditary.

In short, the dietetic cause is by far the most common, and, in prosecuting
inquiries as to the starting-point of an attack, the veterinarian's
attention should be directed in the main to that particular.

_Symptoms_.--Laminitis is always ushered in by a set of symptoms indicative
of a high state of fever. The pulse is raised from the normal to as many as
80 or 90 a minute, muscular tremors are in evidence, the respirations are
short and hurried, and the temperature rises to 105 deg., 106 deg., or 107 deg. F. The
visible mucous membranes are injected, that of the eye, in addition to the
hyperaemia, often tinged a dirty yellow. The mouth is dry and hot, the urine
scanty, and the bowels frequently torpid. As yet, however, the walk is
sound.

Called in during this early stage, the veterinarian is often puzzled as
to the exact significance of the symptoms. Enteritis, lymphangitis, or
pneumonia he knows to be often heralded in the same manner. In this
connection, Zundel says: 'Laminitis, in most instances, is preceded by
certain general symptoms, such as are premonitory of the invasions of
ordinary inflammatory diseases, but of an uncertain significance.'

So far we agree with him, but to what we have already said we would add
that, even in this early stage, there is an additional symptom, unmentioned
by Zundel, which often leads one to an exact diagnosis. The feet are in
turn lifted a short distance from the ground, and almost immediately
replaced. This movement ('paddling,' we may term it) is constant, the
animal appearing to obtain ease in no one position for more than a few
moments at a time.

Seen but a few hours later, when the swelling caused by the hyperaemia
and outpouring of the inflammatory exudate has led to compression of the
sensitive structures within the horny box, the symptoms presented admit of
no misreading, save by the most casual and careless observer. The patient
now stands as though fixed to the ground. The pulse is hard and frequent,
the respirations tremendously increased in number, the body wet with a
patchy perspiration, and the countenance indicative of the most acute
suffering. Only with difficulty, and often only at the instigation of the
whip, can the animal be induced to move. This he does by throwing his
weight, so far as he is able, on to the heels of the feet affected, and
putting the feet slowly forward in a shuffling and feeling manner. The feet
themselves give to the hand a sensation of abnormal heat, percussion upon
them with the hammer is followed by painful attempts at withdrawal, while
any effort we may make to remove one foot from the ground is useless, so
great an aversion does the animal show to placing a greater weight upon the
opposite foot.

According as the front-feet alone, the hind-feet alone, or all four feet
are affected, the symptoms will vary.

With all four feet diseased, the animal stands with the two front-feet
extended in front of him, while the hind-limbs are at the same time propped
as far beneath him as is possible. The horse is, in fact, standing upon the
extreme hindermost portions of the feet.

Why the animal should thus distribute his weight is easily explained.
Standing in the normal position, the body-weight is borne by the sensitive
laminae, the sole, of course, sharing in the burden, but the laminae taking
by far the greater part of the pressure thus exerted. With the vessels of
the laminae gorged with blood, and the laminal connective tissue infiltrated
with a profuse inflammatory exudate, the most excruciating pain is bound
to result by reason of the compression of the diseased tissues within the
non-yielding structures. In some little measure the suffering animal may
afford himself relief by partly removing pressure from the fore-parts of
the hoof. When placing the body-weight behind, the pressure, instead of
falling upon the highly sensitive laminae, is directed to the follicular and
fatty tissues of the plantar cushion: from there, with only a small portion
of the sensitive sole intervening, to the horny frog, and from thence to
the ground.

The same distribution of weight also places the foot in a position of
greatest expansion, thus, by giving greater room to the diseased parts,
again affording relief of pressure on the inflamed lamina, while it at the
same time relieves of weight the foremost portions of the sensitive sole.

With the fore-feet alone attacked, the animal affects exactly the same
position of standing as that just described. The fore-feet are again
extended, and the hind propped far beneath him. The fore extended, in order
to obtain the relief occasioned by standing on the heels; the hind in this
case carried forward in order to take a greater share of the body-weight,
and thus relieve the congested members in front.

With the hind only attacked, then the fore and the hind feet are more
closely approximated than in the normal position. The reason, of course,
is that the hind-feet are carried forward in order to be placed upon the
heels, while the fore are taken backwards to relieve the hind of the
body-weight.

In like manner the movements of the animal will vary with the feet
affected. With only the front-feet diseased the animal is, comparatively
speaking, comfortable. The hind-feet take the weight, and the animal stands
for long periods together, resting alternately first one fore-foot and then
the other, moving often in a circle of which his body is the radius, and
his hind-limbs the centre. If urged to move forward, then immediately his
countenance and movements manifest the pain to which he is put. Only with
reluctance does he cause the fore-feet to take weight. They are shuffled
forward quickly one after the other, so that weight may not be placed
upon them for one instant longer than is necessary, and the hind-limbs
immediately brought again with two short, awkward movements beneath the
body. Progress thus takes place in a succession of movements 'half hobble,'
'half jump.'

Painful though this may appear, progress is still more difficult when the
hind-feet alone are diseased. Afraid that, in placing his fore-members
freely forward, he will add to the pain in his hind, the walk takes place
in a series of extremely short steps, with the feet more or less closely
approximated. The gait is thus rendered extremely awkward, and Zundel, by
saying that 'the animal appears as if treading on sharp needles,' most
fitly describes it.

Movement with all four feet affected, though less awkward in appearance,
is doubtless more painful than in either of the other conditions. Here
the animal can hardly be induced to shift his position at all. Only by
flogging, and that severe, can he be made to go forward. When so induced to
move, the agonizing pain to which the patient is subjected may be gathered
by noting his countenance and manner of progression.

With each movement forward, muscular tremors affect the limbs; each step
is short, jerky, and convulsive; the respirations and pulse are almost
immediately greatly quickened, and the lower lip is hung pendulous, and
moved almost unconsciously up and down with a flapping noise against the
upper. A patchy perspiration breaks out about the body and quarters, and
the tail is outstretched and quivering. At the same time the lines of the
face become drawn, the commissures of the lips pulled upwards, the eyes
staring and haggard, the eyelids puckered, the nostrils extended, and
the whole expression indicative of the intense and agonizing pain of the
disease.

One can perhaps better give one's client some vague idea of the patient's
suffering by likening the pain to the throbbing sensation of a festered
finger-nail. Tell him that each hoof of the horse is similarly, or, if
anything, more delicately, constructed, that in each foot the same process
of 'festering' is going on, and that upon them the animal has perforce to
stand.

As one might expect, the position of greatest ease is the decumbent.
Strange to say, though, in many cases of laminitis the animal persists in
maintaining a standing posture. Once down, however, one has sometimes the
greatest difficulty in persuading him again to rise. The lying position is
so long maintained that bedsores begin to make their appearance, and the
animal rapidly loses flesh, not only by reason of the fever and the pain,
but by giving to rest the time he should normally give to feeding.

Difficulty in rising is greatest when all four feet are affected; is
_nearly_ as great when the hind-limbs only are in trouble, but is least
when the disease exists alone in the two fore-feet.

THE COURSE OF THE DISEASE AND ITS PATHOLOGICAL ANATOMY.--As with
most inflammations of any severity, so with this we may consider the
pathological changes taking place in the foot under three headings: (a)
The period of Congestion; (b) the period of Exudation; (c) the period of
Suppuration.

(a) _Congestion_.--In the early stages of laminitis there is a state of
engorgement of the vessels of the keratogenous apparatus generally, but
more particularly the laminal portion of it. With the hoof removed at this
stage the sensitive laminae are found to be swollen, dark red in colour, and
affording a distinct feeling of increased thickness when pressed between
the fingers, Incised, there escapes from the cut surface a large flow of
dark venous-looking blood. At this stage haemorrhages of the laminal vessels
occur. The escaping blood infiltrates the surrounding connective tissue,
and in many cases destroys the union between the horny and sensitive
laminae. This change is most noticeable in the region of the toe and the
commencement of the quarters, the os pedis appearing as though pushed
backwards by the escaping fluid collected between the wall and the bone. In
severe cases, fortunately but rarely seen, the blood so escaping continues
to infiltrate, and separate the tissues until it is seen to be freely
oozing at the region of the coronet. (See reported case, No. 1, p. 279.)

(b) _Exudation_.--The period of exudation marks the outpouring of the
inflammatory fluid. This, even more than the haemorrhages attending the
stage of congestion, tends to destroy the intimacy between the sensitive
and the horny laminae, leading finally to their complete separation at
the region of the toe. Fig. 116 illustrates this state of affairs after
laminitis has existed for a week. The sensitive and horny laminae are here
shown to be distinctly separated from each other, a well-marked cavity
existing between them, which cavity is greatest in extent at the toe of the
os pedis. With the sensitive structures thus detached from the wall, it is
evident that very much that formerly held the os pedis in normal position
has been destroyed. What then happens is that the whole of the body-weight
is placed upon the sole. Never intended to bear the strain thus imposed,
it naturally sinks. With the sinking is a corresponding 'dropping' of the
pedal bone--in fact, of the whole of the bony column. Seeing that the
structures _above_ the hoof are still normally adherent to the bones, it
follows that they must, as the os pedis sinks, be carried with it. As a
consequence we get a marked depression at the coronet (see Fig. 117, _a_),
which depression may be often noticed after the second or third week of a
severe attack of the disease.

[Illustration: FIG. 116.--LONGITUDINAL SECTION OF A FOOT WITH LAMINITIS OF
EIGHT DAYS' STANDING. The separation between the sensitive structures and
the hoof is indicated by a dark line. The cavity is filled with exudate. It
will be noted that as yet there is little change in the position of the os
pedis.]

Here, again, though to a greater extent than that caused by the haemorrhage
alone, the os pedis appears to be pushed backwards, the space at the toe
between the bone and the horny box being closely filled with the yellow,
slightly blood-stained exudate. This condition is well depicted in Fig.
117.

[Illustration: FIG. 117.--LONGITUDINAL SECTION OF A FOOT WITH LAMINITIS OF
FOURTEEN DAYS' STANDING. _a_, The depression at the coronet caused by the
dropping of the bony column within the horny-box: _b_, a portion of the
sensitive sole pushed downwards and forwards by the descending os pedis.]

With the descent of the os pedis we get in many cases a penetration of the
horny sole (see Fig. 117), leading always to serious displacement of the
sensitive sole (see Fig. 117, _b_), and often to caries of the exposed
bone.

The backward displacement of the os pedis may be accounted for in two ways.
Firstly, the greater vascularity of the membrane covering its front leads
to a greater outpouring of inflammatory fluid in that particular position.
Here, therefore, loss of adhesion with the wall is greatest, while into the
cavity so formed is poured a large quantity of a fluid that is practically
incompressible. The os pedis _must_ be pushed backwards. Secondly, the
manner in which the animal distributes his weight--namely, upon the
heels--is calculated to aid in the bone's backward movement, for with his
feet in this position tension upon the extensor pedis is relaxed, while
that upon the flexor perforans is greatly increased.

(c) _Suppuration_.--Should the animal survive the pain and exhausting calls
made upon his system by the accompanying fever of the foregoing conditions,
the case ends either in resolution or suppuration. When suppuration occurs
it is found, as a rule, at the sole, leading to almost entire separation of
the sensitive and horny structures. The pain, if possible, is even worse
than in either of the foregoing stages, and relief for the suffering
patient is only obtainable by the natural exit of the pus at the coronet,
or by giving it escape with the knife at the sole. As a rule, suppuration
in laminitis is rare, and then only occurs when the disease has been of
some several days' duration. It has been the author's experience, however,
to meet with it in a case but three days' old. This particular animal had
laminitis restricted to the hind-feet. The condition was diagnosed and pus
liberated at the sole of one foot during the third day of the lameness. The
animal was cast on the fourth day, and pus obtained from the sole of the
opposite foot.

_Complications_.--In a moderate case, carefully treated, laminitis
terminates at the end of three or four days in resolution. The general
symptoms of fever gradually subside, the appetite returns, and the walk
becomes easier. Cases thus terminating fortunately leave behind them no
change of serious importance, either in the sensitive tissues or in the
horny envelope. Should resolution, however, be longer delayed, then the
case, although eventually terminating successfully so far as soundness in
gait is concerned, leaves more or less evidence behind in the shape of
rings about the wall and alterations in the build of the sole.

When the happy ending of rapid resolution is denied us, then, in addition
to the condition we have described as suppuration, we may meet with one or
other of the following complications:

_(a) Metastatic Pneumonia_.--This complication is not uncommon, and,
when occurring, more often than not ends fatally. It may be accounted for
indirectly by the greater work the lungs are called upon to perform in
carrying out the increased number of respirations occasioned by the general
fever and pain, and directly by the poisonous materials circulating in the
blood-stream.

_(b) Metastatic Colic_.--This may be either a subacute obstruction of the
bowel or an enteritis accompanied by an offensive purge.

A striking case of the former is related in the _Veterinary Journal_ (vol.
xvi., p. 180) by H. Thompson, of Aspatria. Here no evacuation of the bowels
occurred for three days, and the pains of laminitis were added to by the
usual pains of intestinal obstruction.

The colic of enteritis is in some cases caused by the nature of the food,
giving rise to laminitis. In our opinion, however, it is more often
occasioned by the drastic action of the aloes nearly always resorted to in
the treatment of the disorder. As does the pneumonia, the enteritis thus
brought about nearly always has a fatal termination.

_(c) Gangrene of the Structures within the Hoof_.--This complication is
the one most to be dreaded. It occurs as a result of the great pressure
exerted by an excessive exudation, and doubtless affects first the laminae
and softer structures. Once commenced, however, it rapidly extends to death
of the other structures (ligament, tendon, and even bone), and gives a
fatal ending to the case.

That gangrene of the tissues ("mortification" as our older writers called
it) has occurred is soon made evident to the veterinarian by the symptoms
shown by the patient. The agonizingly acute pains suddenly subside, the
feet are placed firmly and squarely to the ground, and the animal walks
with ease. Perhaps but the night before the patient is seen racked with
excruciating pain; the morning sees the astounding change of apparent
absolute recovery. Too well, however, the eye of the experienced veterinary
surgeon sees that such is not the case. Even before proceeding to take a
record of the other symptoms, he knows that it is but the commencement of
the end. Methodically, however, he notes the other conditions. The pulse
he finds small and imperceptible, save at the radial. The thermometer
registers a subnormal temperature, the extremities are cold, and cold
sweats bedew the body. To the same experienced eye the countenance of the
animal is almost suggestive of what has occurred. The drawn and haggard
expression, to which we have previously referred, becomes more marked, and
the angles of the lips are drawn back in what has been described by some
writers as a 'sardonic' grin.

We can best express what the whole look of the animal's countenance
indicates to us by saying that it gives us the impression that the animal
himself knows that some serious change, and a change fatally inimical to
his chances of life, has taken place in his feet.

It may be that in some odd cases, although it has not yet been our lot to
meet with them, gangrene may terminate in the casting off of one or more
hoofs. Needless to say, there can still be but one termination to the case.

_(d) Periostitis and Ostitis_.--This complication is referred to by other
writers under the term of 'Peditis.' It signifies, of course, that the
periosteum and the bone have become invaded by the inflammatory process.
It is our opinion that these two conditions, even including an actual
arthritis, always exist, even in an attack of laminitis that ends
favourably. We do not claim, however, to be able to relate any means, save
that of post-mortem examination, by which it may be singled out from the
other changes occurring in the foot. The high fever and pain occasioned by
the inroads of the inflammation into the other sensitive structures serves
to effectually mask whatever evidence of it we might otherwise obtain.
It may be sometimes only small in degree, but we feel confident that
inflammation, at any rate of the _outer_ layer of the periosteum, is in
laminitis constant even, we repeat, in a mild case.

[Illustration: FIG. 118.--SHOWING CHANGES IN THE OS PEDIS WITH LAMINITIS OF
LONG STANDING, (_a_, Viewed from the front; _b_, viewed from the side.)
The porous condition of the bone, which is here shown, is a result of a
rarefying or rarefactive ostitis. This specimen also illustrated (what the
photograph cannot show) an accompanying condition of condensation of bone,
or osteoplastic ostitis. (For a fuller description of the changes occurring
in these forms of ostitis, see Chapter XI.)]

When the case is a serious one we have ample evidence to show that ostitis
exists, and exists in a severe form. The bones become vastly altered in
shape, a process of absorption leads to the formation of large, irregular
cavities within their substance, and what of the bone is left is rendered
hard and ivory-like (condensed) near what was the original centre, while
the edges and other portions show often a tendency to become brittle and
porous.

Fig. 118 illustrates the effects of a severe ostitis in pedal bones removed
from hoofs with laminitis of several weeks' standing.

_(e) Chronic Laminitis_.--The most common complication--or, perhaps,
rather we should term it 'sequel'--to acute laminitis is the chronic form
of the disease. For this condition we have reserved a separate section of
our work. It will be found described in Section B 1 of this chapter.

_Diagnosis and Prognosis_.--One is almost tempted to state that the
diagnosis of laminitis offers no difficulty. In the very early stages,
however, it may, as we have already indicated, be mistaken for the oncoming
of Enteritis, Lymphangitis, or even Pneumonia. The paddling of the feet
may help us. If this is absent, however, nothing but a most careful
examination, or, if necessary, the withholding of our opinion until the
following visit will prevent a blunder being made.

Even when well established, laminitis has been mistaken for paralysis,
for tetanus, for rheumatic affections of the loins, or even for some
undiscovered affection of the muscles of the arms and chest. This latter is
no doubt suggested to the uninitiated by the reluctance the animal shows to
move the muscles _apparently_ of that region, and led the older writers to
give to the disease its name of 'Chest-founder.' It is only fair to add,
however, that these blunders in diagnosis are nearly always committed by
persons without a veterinary training.

Thus warned, the veterinary surgeon of average ability should have no
difficulty in establishing a distinction between the diseases we have
enumerated as likely to be confounded with it, and the one this chapter is
describing.

The prognosis in laminitis should, in our opinion, always be guarded. No
advice given in a work of this description can be of any real use, for
every case must be judged entirely on its merits. The severity of
the symptoms, the cause of the attack, the complications, and the
idiosyncrasies of the patient, have all to be taken into account. These the
veterinarian must be left to judge for himself.

_Treatment_.--The treatment of acute laminitis in its early stage must be
based upon the fact that we have to deal with a congested state of the
circulatory apparatus of the whole of the keratogenous membrane. This fact
was well enough known to the older veterinarians. It is not surprising,
therefore, to learn that jugular phlebotomy was at once resorted to as the
readiest means of relieving the overcharged vessels of their blood. As a
matter of fact, bleeding from the jugular is still advocated by modern
authorities. We cannot say, however, that we unhesitatingly recommend it.
Mechanically, of course, the removal of a large quantity of blood is
bound to result in a lowering of the pressure in the vessels. The effect,
however, is but transient. Blood removed in this way is again quickly
returned to the vessels so far as its fluid matter is concerned, and the
pressure, removed for a time, is again as great as before. With the
other and more vital constituents of the blood-stream--namely, the
corpuscles--restoration is not so rapid. We have, in fact, a weakened state
of the system, in which it is probable it will not so successfully combat
the adverse conditions the disease may induce.

With these prefatory remarks, we may advise bleeding under certain
conditions. The quantity removed must be moderate (7 to 8 pints), and the
pulse and other conditions must show no signs of weakness or collapse.

Local bleeding, either from the toe or the coronet, is also advised. In
the former situation the sole is thinned down until a sufficient flow
is obtained, while at the coronet scarification is the method adopted.
Bleeding locally, however, is far less effectual than the jugular
operation. Neither must it be forgotten that wounds in these situations,
more particularly at the toe, are extremely liable, especially with
the existing poisoned state of the blood-current, to take on a septic
character. What might possibly have remained a comparatively simple
inflammation is induced by the operation itself to terminate in the more
complicated and serious condition of suppuration.

Other means of combating the congested state of the membrane are
principally those of local applications. With many veterinary surgeons warm
poulticing is still largely advocated and practised. We do not believe in
it. Warmth, as a means of removing local congestion, can only be successful
when applied _widely_ round the congested area, and so dilating surrounding
bloodvessels and lymphatics. Applied to the congested area itself, and to
that alone, it is almost worse than useless.

With the foot, both around and below it, a surrounding area is denied us.
The only vessels we are able to dilate with the warmth, and so enable them
to carry off the fluid from the congested foot, are those in the
limb above. That poulticing cannot be successfully there applied is
self-evident. Apart from that, it is an open question whether poultices may
not do actual harm in inducing suppuration in cases where, probably, it
would not otherwise occur.

For these reasons we hold to the opinion that when a local application is
determined on it should be a cold one. Various methods of applying cold are
in vogue. Cold swabs are perhaps most in favour. They must, however, be
_kept_ cold. When a suitable water-course, pond, or other expanse of
shallow water is at hand, then the animal may be kept standing therein, or
preferably walked about in it. When suitable apparatus is obtainable, a
constant stream over each foot from a rubber hosepipe is most beneficial.

Astringent baths, containing solutions of alum, of copper sulphate, of iron
sulphate, or of common salt, or composed of a mixture of two or more of the
salts mentioned, may also be used with advantage. In addition to the fact
that such solutions are for a time below the temperature of simple water,
we have the advantage that they have also a more or less antiseptic
property.

While on the subject of the relief of the congestion, we must not forget
to mention a treatment which we ourselves have practised with considerable
success--namely, that of forced exercise. It appears to have been first
brought into prominence by Mr. Broad, of Bath, and the two terms 'Forced
Exercise and Rocker Shoes' and 'Broad's Treatment' have come to be
synonymous.

The Broad shoe is a shoe with a web of quite twice the thickness of the
animal's ordinary shoe, and has this web gradually thinned from the toe
backwards until at the heels the shoe is at its thinnest (see Fig. 119).

The excessive thickness of the shoe serves two purposes. It allows of the
requisite amount of slope being given to the web, and so enables the animal
readily to throw himself back on to his heels, a position in which, as we
have already indicated, he obtains the greatest ease. It also minimizes to
some extent the effects of concussion.

[Illustration: FIG. 119.--SEATED ROCKER BAR SHOE (BROAD'S) FOR TREATMENT OF
LAMINITIS.]

With forced exercise, as practised by Mr. Broad, this shoe is first
applied, and the animal afterwards made to walk upon soft ground, or even
upon the roadway, for a half an hour to an hour and a half three times a
day.

For our own part, we consider the shoe to be almost if not quite
superfluous, so far as its influence upon the progress of the disease is
concerned. We therefore dispense with it, and have the animal exercised in
his ordinary shoes. To do this, the patient has sometimes to be severely
flogged into taking the first few steps. After that progress gradually
becomes easier.

It has been said to be cruel. In so far as we knowingly, and of set
purpose, occasion the animal pain, cruel it undoubtedly is; but it is
cruelty with an aim that is truly benevolent, and the object of our
benevolence is the animal upon whom the cruelty is practised.

One word of advice is needed. The forced exercise must be commenced early.
In the later stages, when the stage of congestion has passed from that
to the acuter stages of the inflammation and the outpouring of the
inflammatory exudate, then forced exercise cannot be safely commenced. The
loss of adhesion between the pedal bone and the horny box, which we know to
be then existent, negatives its advisability.

By many it is advised to always remove the shoes. From what we have already
said, it will be seen that this is not our practice. But one argument
in favour of so doing appears to us to carry weight, and that is that
'dropping' of the sole is probably prevented from becoming so marked. That
condition, however, is entirely dependent upon the changes occurring within
the horny box. It is bound to occur with the animal shod or unshod, and
to reach a stage when only contact with the ground prevents its further
descent. The complication then sometimes following--namely, penetration of
the sole by the bone, is not prevented by having the shoes removed. It may,
in fact, be thus rendered more likely.

Internal treatment consists in the exhibition of suitable febrifuges and
the administration of a dose of aloes.

With regard to the wisdom of the latter proceeding, opinion seems to be
divided. Personally, we hold an open mind concerning it. This much is
certain: in many cases of laminitis--those cases which have their origin
in overfeeding with an irritating food--there is already a strong
predisposition to enteritis. The administration of aloes in this case
is extremely apt to induce a fatal super-purgation. Aloes is, again,
contra-indicated when the laminitis is a result of excessively long
journeys, and the patient is already greatly exhausted. Neither can it be
advocated in the laminitis occurring as a sequel to septic metritis or to
pneumonia.

On the other hand, when the disease has occurred as a result of long
standing in the stable and an overloaded condition of the bowels, or where
one full meal of some constipating food, such as whole wheat, pea or bean
meal, wheat or barley meal, has occasioned the attack, then a dose of aloes
at the commencement of the treatment is productive of good.

Suitable febrifuges are found in potassium nitrate, potassium chlorate,
sodium sulphate, or magnesium sulphate, either of which or a mixture of two
or more of them, the animal will readily take in his drinking-water.

The administration of sedatives is also indicated. In this connection
aconite will be found most useful. More especially in the early stages of
the disease, when pain is excessive and the temperature high, will its
good effects be noticed. This also the animal will often take in his
drinking-water. We have been in the habit of so prescribing the B.P.
tincture in 1/2-dram doses three times daily. By its use the temperature is
rapidly lowered, the pulse reduced in number and in fulness, and the pain
in some instances perceptibly diminished. With others hypodermic injections
of morphia and atropine have given equally satisfactory results.

Needless to say, good nursing is a _sine qua non_. During the first
stages of the fever a light and easily digested diet should be
allowed--bran-mashes, roots and grass when obtainable, and a carefully
regulated supply of water. The animal should be warmly clothed and the box
well ventilated, even to the opening of the doors and windows. Only in this
way is pneumonia as a sequel sometimes prevented. The patient's comfort
should be attended to in providing him with a suitable bed. Anything in
the shape of long litter should be avoided. When nothing else is at hand,
litter that has already been broken and shortened by previous use is best.
With this the box floor should be thickly covered, and matting of the
material prevented by constant turning. A good bed for the horse with
laminitis is peat-moss mixed with short straw. This, without being
dragged into irregular heaps, remains springy and elastic with but little
attention. Better than all, however, especially with good weather, is an
open crewyard. Here the animal has an abundance of fresh air, has a bed
that is always soft, and has plenty of room in which to get up and down
with some degree of ease.

Leaving the dietetic and medicinal, we may consider other treatments of
laminitis that come more particularly under the heading of operative.

The first matter that here demands our attention is that of allowing the
exudate to escape at the sole. If after the expiration of three or four
days pain and other symptoms of distress continue, then it may be judged
that the inflammatory exudate has made its appearance. Operative measures
allowing of its escape, though not giving absolute ease, do undoubtedly
relieve the more marked expressions of suffering, and should be at once
determined on. To do this completely it is necessary to cast the animal.
The sole is then thinned at the toe with the drawing-knife until the
sensitive structures are reached. A flow of yellow and sometimes
blood-stained discharge is immediately obtained, and the sole itself found
to be underrun to a considerable extent. An opening sufficiently large to
admit of free drainage (about the size of a half a crown-piece) is made,
the wounds antiseptically dressed, and the hobbles removed.

If showing an inclination to do so, the animal should then be allowed
to remain and rest. In one instance in which we so operated (a case of
laminitis in the hind-feet alone), the relief given was at once manifested.
For three days previously the animal had remained standing in agonizing
pain. On the fourth he was cast, and the discharge--partly inflammatory
exudate, and partly a sanious foetid pus--liberated. The hobbles were
removed, and the animal allowed to remain down while our attention was
drawn to another case. This attended to, we walked back to the field
where, our first patient was lying. His breathing, but a short time before
distressedly short and catching, was now so slow and deeply regular that
for one brief moment the thought flashed across our mind that he was dead.
He was in a _profound_ sleep.

Other operators sometimes give the exudate escape while making the grooves
in what is now known as 'Smith's Operation.'

In this operation the hoof is so grooved as to allow of its expansion, so
relieving the pressure on the sensitive structures within it. Incidentally,
the inflammatory exudate is given exit.

[Illustration: FIG. 120.--DIAGRAM OF HOOF SHOWING THE POSITION OF THE THREE
GROOVES MADE IN THE TREATMENT OF LAMINITIS.]

The animal is cast, the shoes removed, and three vertical grooves made
in the wall. The first is cut down the centre of toe, extending from the
coronet to the ground surface. The second is made to the right of this, and
the third to the left, each following the direction of the horn fibres, and
each distant about 2 inches from the first (see 1, 2, and 3, Fig. 120).

Each of the grooves must run completely from the coronary margin to the
ground surface, and each should be carried through the substance of the
horn until the horny laminae are reached. This done, the underneath surface
of the foot is grooved at the white line (see curved groove 4, Fig. 121)
in such a manner as to entirely isolate the two pieces of horn _a_ and _b_
from the remainder of the hoof.

Expansion of the horny box is thus brought about, while at the same time
the semicircular groove at the toe is made deep enough to allow of the
escape of the exudate.

If thought wise by the operator, the two pieces of horn _a_ and _b_ may be
isolated, and the exudate given exit by making the fourth groove in the
position of the dotted lines in Fig. 120--that is to say, at the lowermost
portion of the sensitive structures. By this means the sole will be left
intact.

[Illustration: FIG. 121.--LOWER SURFACE OF FOOT SHOWING POSITION OF THE
GROOVES MADE IN THE TREATMENT OF LAMINITIS.]

Fuller instruction for making the grooves and the instruments required will
be found described in Section C of Chapter X.

The animal should be afterwards shod, and the bearing on the portions
_a_ and _b_ of the wall removed. Almost immediate relief is afforded the
patient.

_Recorded Cases_.--1. 'On the evening of September 28 last, I was called
rather hurriedly to attend a posting-horse which had just arrived from a
twenty-one miles' journey, and was said to be "very ill." I lost no time in
proceeding to the spot, and found my patient "very ill" indeed. No need for
long consideration as to diagnosis; the symptoms showed at once that I had
an uncommonly severe case of acute founder before me. On examination I
found the pulse was 120, the respirations 100, and the thermometer 106 deg. F.
The poor brute could not move, the fore-legs were well out before, and the
hind-legs thrown back behind; in fact, he was, as one might say, propping
himself up with his four legs!

'On examining his feet, I discovered what I had never either seen or heard
of before--namely, _blood freely oozing out_ at the coronet of all four
feet; if anything, the hind-feet were the worst, and, showing that this
bloody discharge at coronets had commenced during progression and before
he was stabled, the inside of the thighs were all shotted over with blood,
which had been thrown up by his feet while he was trotting or walking. He
was completely soaked all over with perspiration.

'My prognosis could not well be otherwise than unsatisfactory. I resolved,
however, to do all I could to relieve the poor suffering brute. As a matter
of course, jugular phlebotomy was utterly impracticable; so, to relieve the
pressure in the feet, I had him (after, with extreme difficulty, removing
the shoes) bled, or rather opened, at all four toes, and hot poultices
applied. On opening the off-side toe, in both hind and fore feet, I found
an escape of very dark-coloured blood, with a great many bubbles of gas,
thus showing that the destructive process was fairly established in the
two bony extremities mentioned. The near fore and near hind feet showed no
signs of gas-bubbles on being opened at the toe.

'I gave a laxative in combination with a diffusible stimulant, and ordered
doses of aconite and potassium iodide; I also applied strong sinapisms to
each side, immediately behind the shoulders. After three hours I found my
patient rather easier; respiration about 90, and temperature 104 deg.; willing
to take a little water, and even attempted to take some hay. Ordered
continued applications of hot water to the poultices at feet, and
clothed him up for the night. Next morning there was little improvement;
respirations over 80, and temperature 103.5 deg.. Continue same treatment.
Second morning, horse apparently easier; temperature 102.5 deg., but very
difficult respiration; laxative had operated during the night; ordered
diffusible stimulants. About two hours and a half after my last visit, the
horse turned round in his stall and dropped down dead!

'_History of the Horse_.--He belonged to an extensive horse-hiring
establishment; was purchased a short time before for L60--a long price for
a post-horse--had recently suffered and been off work from some "severe
cold"; was taken out, and did forty-seven miles of a journey the day
_before_ I saw him; on forenoon of the day on which he was attacked he did
two or three short turns, and then twenty-one miles of a journey in the
afternoon, during which he became so ill as scarcely to be able to conclude
the twenty-one miles; this was the last turn he was to do. He was a grand
stepper, and no doubt was pushed a little during this final journey, as
the driver intended, after a short rest, to finish off with the twenty-six
miles between this and home. With the short turns on the second forenoon,
this would have been over 100 miles in less than two days, with a horse
just out of a _severe cold_.'[A]

[Footnote A: _Veterinary Journal_, vol. xvii., p. 314 (A.E. Macgillivray).]

2. 'Whilst attending a patient on a farm on September 5 last my attention
was called to a cart-horse, five years of age, that had been castrated in
the standing position by a travelling castrator about ten days previously.

'I found the animal presenting the following symptoms: Head down, blowing
hard, very dull, and disinclined to move, temperature 105 deg. F., hard, rapid,
slightly irregular pulse, membranes injected, appetite lost; scrotum,
sheath, and penis tremendously swollen, castration wounds unhealthy, and
exuding a thin, reddish-brown discharge of a most foetid odour.

'The next day well-marked symptoms of laminitis were present. I finally
ceased attending him about the middle of October, and at the end of that
month he was turned out for the winter.'[A]

[Footnote A: _Veterinary Record_, vol. xiv., p. 649 (Charles A. Powell).]

3. 'On July 8 an interesting case of laminitis came under my notice. The
subject was a mare, eight years old, which had been running on the common
here for some months, and was taken up on the night of July 2 by a boy,
who did not observe anything amiss with her. The following morning, on the
owner going to the stable, he found the animal in great pain, and at once
sent for me. I discovered her to be suffering from laminitis, and saw her
again in the evening, when she was much worse. The attack proved to be a
most severe one.

'The owner informed me that she had not been allowed any corn for two
months, and that she had no distance to travel on the road from the common.

'Though on such a poor pasture, the mare was very fat; she had never been
unwell before this attack.

'This is the first case I have seen of laminitis occurring when the animal
was on grass.'[A]

[Footnote A: _Veterinary Journal_, vol. ix., p. 176 (W. Stanley Carless).]


B. CHRONIC.

1. CHRONIC LAMINITIS.

_Definition_.--A low and persisting type of inflammation of the sensitive
structures of the foot, characterized by changes in the form of the hoof,
and incurable pathological alterations within it.

_Causes_.--Chronic laminitis more often than not is a sequel to the acute
form we have just described. With an attack of acute laminitis that defies
treatment, and does not end in resolution in from ten days to a fortnight,
then the chronic form may be expected.

The brittle horn, convex sole, and other changes we have described under
Pumiced Foot may, however, be regarded as a chronic laminitis, and this
condition, as we have already indicated in Chapter VI., may run a course
slow and insidious from the onset.

_Symptoms_.--When the disease arises without previous acute symptoms, the
first thing noticeable is an alteration in the gait. The animal begins to
go feelingly, especially when first moved out from the stable. Our opinion
is asked as to the cause of the lameness, and an inspection is made. With
the changes in the form of the hoof as yet wanting, we have nothing to
guide us, and other causes for the lameness suggest themselves, probably
corns. Evidence of these is not forthcoming, and we in all probability
withhold our opinion until a later visit. On the second or a subsequent
call we are perhaps lucky enough to find our patient down. Diagnosis is
then rendered easier. Made to rise, the animal stands in the attitude we
have described as indicative of laminitis. We have him walked and trotted
out. The symptoms of tenderness disappear, and the animal soon goes fairly
sound. He is, in fact, workable--that is, by anyone who is careless as to
the comfort of his beast.

When following an acute attack, we have the most marked symptoms of pain
and distress, somewhat abating after the second or third week. The walk,
however, is still painful, and, for a short time after rising from the
ground, even difficult.

In short, in both cases we have the horse going on his heels, with a walk
that is painful, and with symptoms of pain that are most apparent when
moved on after a rest.

Later, the changes in the form of the hoof begin to appear. It seems to
have lost its elasticity, and is seen to be dry and chippy, and to have
become denuded of its varnish-like outer covering.

In addition, it is of largely altered shape. The toe, by reason of the
animal walking on his heels, and by reason of an increased growth of horn,
becomes elevated, so that the front of the wall, instead of forming an
obtuse angle with the ground, comes to run very nearly horizontal with
it. The horn of the heels, as compared with that of the toe, takes on an
increased growth. The same thing we have already indicated as happening at
the toe, though in lesser degree. Taken together, this increased growth of
horn at the toe and at the heels has the result of lengthening the diameter
of the foot from before backwards, the transverse diameter remaining more
or less normal. The hoof thus loses its circular build, and comes to
approach nearer an elongated oval.

[FIG. 122.--FOOT BADLY DEFORMED AS A RESULT OF CHRONIC LAMINITIS.]

At this stage, too, the pathological 'ribbing' of the hoof is observable.
The outer surface of the wall becomes marked with a series of ridges
encircling the hoof from heel to heel (see Fig. 81, which illustrates a
moderate deformity of the hoof occurring after laminitis). In the badly
laminitic hoof, however, this deformity is largely increased, until in some
cases the shapeless mass can hardly be likened to a foot at all (see Fig.
122).

The inferior or solar surface of the foot also offers certain changes for
our consideration. The first thing that strikes one is the convexity of the
sole. This, as we have already pointed out, is due to descent of the os
pedis, and the highest point of the convex portion is that immediately in
front of the apex of the frog. Here the horn is sometimes found to be quite
yielding to the finger, is excessively thin, and is more or less granular
and inclined to break up under manipulation. As a consequence, any rough
use of the drawing-knife, or an accidental wounding with sharp flints or
stones, leads to exposure of the sensitive structures and local gangrene.

With the horn of the sole thus deteriorated by reason of excessive and
continued pressure upon the parts secreting it, it is not surprising to
find that, in many cases, actual penetration of it with the os pedis
occurs. It is the anterior portion of the inferior margin of the bone that
makes its appearance, and shows itself as a small semicircular white or
dark gray line on the sole.

[Illustration: FIG. 123.--SOLAR ASPECT OF FOOT WITH CHRONIC LAMINITIS,
SHOWING ITS ABNORMAL OVAL SHAPE FROM BEFORE BACKWARDS, AND THE EXCESS OF
HORN GROWING FROM THE WHITE LINE IN THE REGION OF THE TOE.]

Exposure of the bone is soon followed by its necrosis, in which case the
wound takes on an ulcerating character. From it there is a discharge of
pus, black in colour and offensive in smell, and, protruding from the
opening, are excessive granulations of the remains of the sensitive sole.

The 'white line,' so apparent when a normal foot is cleaned with the knife,
can no longer be sharply distinguished from the surrounding horn, while in
some cases the horn composing it takes on an abnormal growth at the toe
(see Fig. 123). This adds still further to the abnormal lengthening of the
antero-posterior diameter of the foot already mentioned.

In other cases horn in this position is altogether wanting, and in its
place is a well-defined cavity, into which the blade of a knife can be
readily passed. This cavity is bounded in front by the original wall of the
hoof, and is here lined by a degenerated and hypertrophied growth of the
horny laminae. Posteriorly the cavity is bounded by the front of the os
pedis, and is lined by a thin growth of horn secreted by the keratogenous
membrane covering the bone. Superiorly the cavity is quite narrow,
and extends to near the lower surface of the coronary cushion, while
inferiorly, at its open portion, it is often 1/2 inch to 1 inch wide.
Laterally it extends on each side of the toe to the commencement of the
quarters.

[Illustration: FIG. 124.--LONGITUDINAL SECTION OF A FOOT WITH LAMINITIS OF
THREE WEEKS' STANDING. On the anterior face of the cavity, in front of
the os pedis, are thickened horny laminae. Due to the sinking of the bony
column, the os pedis has perforated the horny sole.]

Exploration with a director, or with the blade of a scalpel, removes from
the opening a dry detritus. This is composed of the solid constituents
of the escaped blood, the dried remains of the inflammatory exudate, and
broken-down fragments of cheesy-looking horn. The size to which the cavity
may sometimes extend is illustrated in Fig. 124. The thickened horny laminae
forming the anterior boundary of the cavity are here depicted, together
with commencing perforation of the horny sole by the os pedis. It is this
cavity which, when opened at the bottom and discharging its mealy-looking
contents, is known as seedy-toe, for a further description of which see p.
293.

The lameness occurring with chronic laminitis does not always persist. As
time goes on the sensitive structures accommodate themselves to the altered
form and conditions of the horny box. In certain situations--namely, where
pressure is greatest--the softer structures become atrophied, and sometimes
even wholly destroyed; while in other positions the changes in form of the
hoof tend to increase in size of its interior, with a consequent diminution
of pressure upon, and increased growth of the structures within it.

_Pathological Anatomy_.--In detailing the changes to be observed in chronic
laminitis, we take up the description where we left it when dealing with
the pathological anatomy of the acute form. The alterations to be met
with are best observed by taking a foot so diseased and making of it two
sections--one longitudinal, from before backwards; the other horizontal,
and in such a position as to cut the os pedis through at its centre.

These sections will expose to view the cavity formed by the pouring out of
the exudate, and its full extent may be noticed by examining the sections
alternately. Taking the horizontal section first, it will be seen that
the hollow space extends wholly round the toe, and as far back as the
commencement of the quarters. In the latter position one is able to observe
laminae still in their normal positions and condition. At the toe, however,
the horny and secretive laminae are widely separated, and the space between
them filled with a yellow, semi-solid material, the remains of the
inflammatory exudate and new horn secreted by the keratogenous membrane.
The laminae, both horny and sensitive, are greatly enlarged. This is a
hypertrophy, resulting from the continued effects of the inflammation, and
leads in time to the formation of laminae quite three or four times their
normal size. It is this hypertrophy of the laminae and the pressure of the
exudate that causes the bulging and increased growth of the horn at the toe
(see Fig. 125), and contributes towards the oval formation of the foot we
have mentioned before.

[Illustration: FIG. 125.--LONGITUDINAL SECTION OF A FOOT WITH LAMINITIS OF
SEVERAL YEARS' DURATION.]

In the longitudinal section the first thing noticeable is the change
in position of the bones, more especially in that of the os pedis. The
circumstances we have mentioned before--pressure of the exudate upon it in
front and tension of the perforans on it behind--have caused it to assume
a more upright position than is normal, so much so that in a bad case the
front of the bone becomes quite vertical. This vicious direction the other
bones of the digit follow (see Fig. 125).

Consequent upon the displacement of the bone, the plantar cushion, by
reason of the continued pressure thus put upon it, becomes atrophied, while
its hinder half is, as it were, squeezed into taking up a position
more posterior and higher in the digit than normally it should. The
horn-secreting papillae covering its inferior face thus become directed
backwards sooner than downwards, in which way we account in some measure
for the noticeable increase of horn at the heels.

_Treatment_.--Chronic laminitis is incurable. Treatment must therefore be
directed towards the palliation of such conditions as are present, with
the object of rendering the the animal better able to perform work. When
perforation of the sole has occurred, with the attendant formation of pus
and necrosis of the os pedis, it is doubtful whether treatment of any kind
is advisable. There are on record cases of this description, where careful
curetting of the exposed and necrotic portions and the after application of
antiseptic dressings, held in position by a plate shoe or a leather sole,
has been followed by good results, and the animal restored for a time to
labour. In our opinion, however, early slaughter is the most economical
course to adopt, and certainly the wisest advice to give to the ordinary
client.

When perforation of the sole is absent, and when serious alteration in the
shape of the horny box has not occurred, then the most simple treatment is
to put the animal straight away to slow work, with the feet protected by
suitable shoes.

Here, again, the most useful shoe is the Rocker Bar (Fig. 119). The broad
web and deep seating gives ample protection to the convex sole, and with
the ease in distributing his weight that this shoe affords the animal is
able to perform slow work on soft lands with some degree of comfort.

Should the growth of the horn at the toe and at the heels be unduly
excessive, then our attention may be directed towards reducing it to some
approach to the normal. This is accomplished by removing with the rasp and
the knife those portions indicated by the dotted lines in Fig. 127. Here it
will be seen that the bulk of the horn removed is that protruding at
the toe. After this the animal should again be suitably shod. In this
connection it should be noted that the fact of the animal walking largely
on the heels tends to a forward displacement of the shoe. This must be
prevented by providing each heel of the shoe with a clip, after the manner
shown in Fig. 128; or, in the case of a bar shoe, supplying it with a clip
at the centre of the bar.

[Illustration: FIG. 126.--DIAGRAM ILLUSTRATING THE ABNORMAL GROWTH OF HORN
AT THE TOE AND HEELS OF THE FOOT WITH CHRONIC LAMINITIS.]

[Illustration: FIG. 127.--THE SAME FOOT AS IN FIG. 126. The dotted lines
show the excess of horn removed preparatory to shoeing.]

Among other treatments to be noted we may mention one or two to be found
chiefly in Continental works on this subject.

The method of Gross consists in thinning down with a rasp about 1-1/2
inches of the horn of the wall immediately below the coronet, the thinned
portion extending from heel to heel. The groove made is filled with
basilicon ointment,[A] and the coronet stimulated with a cantharides
ointment, In this way there is induced to grow from the coronet a new wall
of nearly normal dimensions.

[Footnote A: Basilicon ointment is made by heating together resin 8 parts,
beeswax 8 parts, olive oil 8 parts, and lard 6 parts. Allow to cool without
stirring.]

By other operators (Bayer, Imminger, Meyer, and Gunther) this treatment
has been modified by enlarging upon it and removing the whole of the
adventitious horn.

[Illustration: FIG. 128.--THE SHOE WITH HEEL-CLIP.]

This is done by means of the drawing-knife and the rasp, the ugly-looking
pumiced foot being carefully cut and trimmed until, so far as outward
appearances are concerned, it is perfectly normal. This done, the whole
foot is treated with a suitable hoof ointment, and a shoe applied that
affords protection to the sole without imposing pressure upon it. The
shoe indicated is either an ordinary shoe with an unusually broad and
well-seated web, or the seated Rocker Bar of Broad. With either it is well
to additionally protect the sole by means of a leather or rubber pad and
tar stopping, or by using the Huflederkitt described on p. 148. In every
case the nails must be kept well back in order to avoid the weakened and
degenerated horn at the toe, and to take advantage of the greater growth of
horn at the heels.

The wisdom of thus removing the whole of the adventitious horn may be
questioned. Although a foot of a nearly normal shape is obtained, it must
be remembered that the grave alterations within it are unchanged, and
that in certain positions the operation must have carried us nearer the
sensitive structures than is advisable.

All other treatments failing, the operation of neurectomy has been advised.
This we do not think wise. One would imagine that, with degenerative
processes already going on in the foot, the tendency to gelatinous
degeneration, always to be looked for in neurectomy, would be increased.
This, as a matter of fact, is the case, and is borne out by the statements
of those who have tried this method of treatment. In many cases the
lameness even is not got rid of. Even where it is, the operation is
afterwards followed by a great tendency to stumble, by sloughing of the
hoof, or by a marked increase in the adventitious horn, and a consequent
greater deformity of the foot.

Sooner than risk neurectomy, it seems to us wiser to give a trial to the
operation advocated by M.G. Joly, namely, that of ligaturing one of the
digital arteries on each affected foot. This operation is performed in the
same position as is the higher operation of plantar neurectomy, and may be
either internal or external. The vessel is exposed, and a double ligature,
preferably of silk, placed on it. The artery is then divided between
the two ligatures. The immediate effect of the operation is to cause
a considerable diminution in the arterial pressure, and so lessen the
intensity of the ostitis in the os pedis. Its consequences are not so
serious as those of neurectomy, and it decongests tissues which neurectomy
congests.

In cases related by M. Joly this operation, practised both in conjunction
with removal of the excess of horn and without it, has resulted in a marked
improvement in the gait, the animal going to work one month after the
treatment, and remaining sound for some time afterwards.

2. SEEDY-TOE.

_Definition_.--A defect in the horn of the wall, usually at the toe, but
occurring elsewhere, resulting in loss of its substance in either its
internal or external layers (see Figs. 129, 130, and 131).

_Causes_.--The most common factor in the causation of this defect is
undoubtedly disease of the sensitive laminae. We have, in fact, just given
an excellent example of the formation of a seedy-toe in the sections of
this chapter devoted to laminitis (see pp. 265 and 286). The cavity here
formed by the outpouring of the inflammatory exudate and the separation of
the sensitive and horny laminae persists. It becomes filled with the
dried remains of the exudate and perverted secretions from the horny and
sensitive laminae (see p. 287). As yet, however, the cavity is closed below,
and its existence only surmised. Later, with successive visits to the
forge, the layer of solar horn forming its floor is cut away, and the
cavity exposed to view. Its mealy-looking contents are removed, and the
case reported by the smith.

Although occurring in this way with an acute attack of laminitis, it must
be remembered that seedy-toe may arise without previous noticeable cause.
The first intimation the owner has is a report from the forge that
seedy-toe is in existence. To refer to cases so arising a probable cause is
far from easy. At one time it was believed to be due to parasitic infection
of the horn. Others have blamed the pressure of the toe-clip, excessive
hammering of the wall, or pressure from nails too large or driven too
close. Others, again, say that seedy-toe may result from a prick in the
forge, from hot-fitting of the shoe, from standing on a dry and sandy soil,
or from the use of high calkins on the front shoes. In these cases--cases
with an insidious onset--we are inclined to the opinion that the disease
of the horn commences from below, and that the sensitive laminae become
implicated later. Holding this view, one must account for the commencing
disease of the horn by giving, as causes, firstly, those factors (as,
for instance, alternate excessive dampness and dryness) leading to
disintegration of the horn tubules; secondly, the penetrating into and
between the degenerated tubules of parasitic matter from the ground; and,
thirdly, the final breaking up of the horn, and spread of the lesion under
the invasion thus started.

[Illustration: FIG. 129.--DIAGRAM ILLUSTRATING POSITION OF SEEDY-TOE
(INTERNAL). 1, The horn of the wall; 2, the horn of the sole; 3, the cavity
of the seedy-toe; 4, the os pedis; 5, the keratogenous membrane.]

_Symptoms_.--Lameness sometimes attends seedy-toe, and sometimes does not.
This is an important point to be carried in mind by the veterinary surgeon
who is accustomed in his practice to have many animals pass through his
hands for examination as to soundness. An animal with advanced seedy-toe--a
condition constituting serious unsoundness--may walk and trot absolutely
sound, and may give no indication, either in the shape of the wall or the
condition of the sole, that anything abnormal is in existence. Later,
however, after the veterinary surgeon has passed him, the purchaser lodges
the complaint that the horse has a bad seedy-toe, which, so he is told,
must have been there for some time. In this case, culpable though he may
appear, there is every excuse for the veterinary surgeon.

Once the cavity is opened at the toe in the neighbourhood of the white
line, then diagnosis is easy. A blunt piece of wood, the farrier's knife,
or a director may be easily passed into it, sometimes as far up as
the coronary cushion (see Fig. 129). Issuing from the opening is seen
occasionally a little inspissated pus; more often, however, the dry,
mealy-looking detritus to which we have before referred. This form of the
disease we may term 'Internal Seedy-Toe.' for, plainly enough, it has had
its origin in chronic inflammatory changes in the keratogenous membrane.

[Illustration: FIG. 130.--EXTERNAL SEEDY-TOE COMMENCING AT THE PLANTAR
BORDER OF THE WALL.]

[Illustration: FIG. 131.--EXTERNAL SEEDY-TOE COMMENCING ON THE ANTERIOR
FACE OF THE WALL.]

Disease of the horn and loss of its substance may, however, also commence
from without. A report on this condition, under the title of 'External
Seedy-Toe,' is to be found in vol. xxix. of the _Veterinary Journal_, from
which we borrow Figs. 130 and 131.

In Fig. 130 it will be seen that the disease commences at the plantar
surface of the toe, and extends upwards and inwards. The same condition
may also appear anywhere between the coronet and the ground, gradually
extending into the substance of the wall, as shown in Fig. 131. According
to the writer, Colonel Nunn, the progress of the disease in this latter
case appears to be faster in a downward than in an upward direction. This,
however, is more apparent than real, as the rate of growth of the horn
downwards detracts from the progress of the disease upwards, although it
spreads over the horn at the same rate.

Before concluding the symptoms, we may again allude to the fact that,
although usually occurring at the toe, the same condition may be met with
in other positions--namely, at either of the quarters. In appearance and in
other respects it is identical with that occurring at the toe.

When the animal is lame and the existence of seedy-toe is surmised, or when
the cause of the lameness is altogether obscure, a little information may
perhaps be gathered from noting the wear of the shoe. If the animal has
been going lame for any length of time as a result of disease in the
sensitive laminae, then the shoe will be greatly thinned at the heels, and
the toe but little worn.

_Treatment_.--As with diseased structures elsewhere, the most rational
treatment, when possible, is that of excision. The entire portion of the
wall forming the anterior boundary of the cavity is thinned down with
the rasp and afterwards removed with the knife, wholly exposing the
hypertrophied, but usually soft layer of horn covering the sensitive
structures. These hypertrophied portions are also removed, and every
particle of the dust-like detritus cleaned away. After-treatment consists
in dressing the parts with a good hoof ointment, protecting them, if
necessary, with a pad of tow and a stout bandage. It may be that the
removal of a large portion of the wall may for some time throw the animal
out of work. Acting on Colonel Fred Smith's suggestion, this may be avoided
by having made a thin plate of sheet-iron, slightly larger in circumference
than the portion of horn removed, and shaped to follow the contour of the
foot. This made, it is sunk flush with the wall by hot-fitting it, and kept
in position by several small steel screws fixed into the sound horn, just
as in the treatment for sand-crack (see p. 174). This will serve the
useful purpose of maintaining in position any dressing that may be thought
necessary, of acting as a support to the horn left on each side of the
portion removed, and of keeping the exposed structures free from dirt and
grit.

Practical points to be remembered in fitting plates of this description
to the feet are: The plate must never quite reach the shoe, or it will
participate in the concussion of progression, and so loosen the screws that
hold it in place. For the same reason, that portion of the sole adjoining
the piece of horn removed must have its bearing on the shoe relieved. The
screws holding the plate should be oiled to prevent rusting, and should
take an oblique direction in order to obtain as great a hold as possible on
the wall.

When excision is deemed unwise or unnecessary, treatment should be directed
towards maintaining the cavity in a state of asepsis. To this end it
should be thoroughly cleaned of its contents, and afterwards dressed with
medicated tow. The ordinary tar and grease stopping is as suitable as any.
This, together with the tow, is tightly plugged into the opening and kept
in position by a wide-webbed shoe. Instead of the tar stopping and the tow,
there may be used with advantage the artificial hoof-horn of Defay (see p.
152). Before using this the cavity should again be thoroughly cleaned out,
and should in addition be mopped out with ether. The latter injunction is
important, as unless the grease is thus first removed, the composition will
fail to adhere to the horn. With the cavity thus cleaned and prepared, the
artificial horn, melted ready to hand, is poured into it and allowed to
set.

In every case, no matter what else the treatment, the bearing of the horn
adjacent to the lesion should be removed from the shoe.

Whether practising the method of plugging the cavity or that of excision of
the wall external to it, attempts to quickly obtain a new growth of horn
from the coronet should be made. To further that, frequent stimulant
applications should be used. Ointment of Biniodide of Mercury 1 in 8, of
Cantharides 1 in 8, or the ordinary Oil of Cantharides, either will serve.

3. KERAPHYLLOCELE.

_Definition_.--By this term is indicated an enlargement forming on the
inner surface of the wall. In shape and extent these enlargements vary.
Usually they are rounded and extend from the coronary cushion to the sole,
sometimes only as thick as an ordinary goose-quill, at other times reaching
the size of one's finger. Often they are irregular in formation and
flattened from side to side.

[Illustration: FIG. 132.--A PORTION OF THE HORN OF THE WALL AT THE TOE
REMOVED IN ORDER TO SHOW A KERAPHYLLOCELE ON ITS INNER SURFACE.]

_Causes_.--Keraphyllocele is very often a sequel to the changes occurring
at the toe in laminitis. Probably, however, the most common cause is an
injury upon, or a crack through, the wall. It may thus occur from excessive
hammering of the foot, from violent kicking against a wall or the stable
fittings, and from the injury to the coronet known as 'tread.' It may also
occur as a sequel to complicated sand-crack, and to chronic corn.

That fissures in the wall are undoubtedly a cause has been placed on record
by the late Professor Walley, who noticed the appearance of these horny
growths following upon the operation of grooving the wall.[A]

[Footnote A: _Journal of Comparative Pathology and Therapeutics_, vol. iii,
p. 170.]

This gentleman had a large Clydesdale horse under his care for a bad
sand-crack in front of the near hind-foot, and, as the lameness
was extreme, he adopted his usual method of treatment--viz., rest,
fomentations, poulticing, and the making of the V-shaped section through
the wall, and subsequently the application of an appropriate bar shoe
to the foot, and repeated blisters to the coronet. In a short time the
lameness passed off, and the horse was put to work. A few days later the
animal met with an accident, and was killed.

On examining a section of the hoof it was found that a vertical horny ridge
corresponding to the external fissure had been formed on the internal
surface of the wall, and that a well-marked cicatrix extended upwards
through the structure of the hoof at the part forming the cutigeral groove;
furthermore, _a similar ingrowth had been taking place in the line of the
oblique incisions made for the relief of the sand-crack_.

This case has an important bearing on the operation of grooving the wall,
which operation we have several times in this work advocated for the relief
of other diseases. It teaches us that the incisions should not be carried
so completely through the horn as to interfere with and irritate the
sensitive laminae, and so set up the chronic inflammatory condition leading
to hypertrophy of the horn.

From the position on the os pedis of the indentation made in it by the
keraphyllocele (see Fig. 133) it has been argued that pressure of the
toe-clip is a cause of the new growth. This, we should say, cannot be a
very strong factor in the causation, for, while we admit that the continual
pressure of the clip, and the heavy hammering that sometimes fits it into
position, is likely to set up a chronic inflammatory condition of the
sensitive laminae in that region, we must still point out that the rarity
of keraphyllocele, as compared with the fact that clips are on every shoe,
does not allow of the argument carrying any great weight.

_Symptoms_.--Except under certain conditions this defect is difficult
of detection. As a rule, lameness is not produced by it. In making that
statement we are led largely by the conclusion arrived at by Professor
Walley. This observer noted the fact that ingrowths of horn such as we are
describing nearly always take place in false quarter, or after a sand-crack
has been repaired, and that they commonly occur after the operation of
grooving the wall in the manner we have just shown.

Now, we know that quite often under these circumstances the horse goes
perfectly sound. Thus, while we know that in all probability keraphyllocele
is in existence, we have ocular demonstration that the animal is quite
unaffected by it.

In some cases, however, lameness is present. During the early stages of
the growth's formation it is but slight, increasing as the keraphyllocele
enlarges. Should this be the case, other symptoms present themselves.
The coronet is hot, and tender to the touch, sometimes even perceptibly
swollen, and percussion over the wail is met with flinching on the part
of the animal. In other cases one is led to suspect the condition by
the prominence of the horn of the wall of the toe. This is distinctly
ridge-like from the coronet to the ground, while on either side of it the
quarters appear to have sunk to less than their normal dimensions. We
believe this to be an illusion, as a ridge of any size at the toe readily
gives one the impression of atrophy behind it, without this latter
condition being actually present.

Should this ridge-like formation and the accompanying symptoms of pain and
lameness occur after repair of a sand-crack, then keraphyllocele may, with
tolerable certainty, be diagnosed. When these outward signs are wanting,
however, and the true nature of our case is a matter of mere conjecture, a
positive diagnosis may still be made at a later stage--that is, when the
abnormal growth of horn reaches the sole. In this case either there is
met with when paring the sole a small portion of horn, circular in form,
distinctly harder than normal, and indenting in a semicircular fashion the
front of the white line at the toe, or solution of continuity between the
tumour and the edge of the sole and the os pedis takes place, and the
lameness resulting from the ingress of dirt and grit thus allowed draws
attention to the case.

_Pathological Anatomy_.--With the sensitive structures removed from the
hoof by maceration or other means, these growths are at once apparent. They
may occur in any position, but are usually seen at the toe, and they may
extend from the coronary cushion to the sole, or they may occupy only
the lower or the upper half of the wall. In places the tumour (or 'horny
pillar' as the Germans term it) is roughened by offshoots from it, and does
not always exhibit the smooth surface depicted in Fig. 132. Commonly, the
horn composing the new growth is hard and dense. Sometimes, however, it is
soft to the knife, and is then found to be itself fistulous in character,
a distinct cavity running up its centre, from which issues a black and
offensive pus.

In a few cases the sensitive laminae in the immediate neighbourhood are
found to be enlarged, but in the majority of cases atrophy is the condition
to be observed. Not only are the sensitive structures found to be shrunken
and absorbed, but the atrophy and absorption extends even to the bone
itself (see Fig. 133). This latter is a result of the continued pressure of
the horny growth, in a well-marked case ending in a sharply-defined groove
in the os pedis in which the keraphyllocele rests. The fact that the softer
structures, and even the bone, thus accommodate themselves to the altered
conditions is, no doubt, the reason that lameness in many of these cases is
absent.

_Treatment_.--It is doubtful whether anything satisfactory can be
recommended. When we have suspected this condition ourselves, it has been
our practice to groove the hoof on either side of the toe, after the manner
illustrated in Fig. 120, and, at the same time, point-firing the coronet
and applying a smart cantharides blister. Certainly, after this operation,
lameness has often disappeared--whether, however, as a result of the
treatment adopted or by reason of the structures within accommodating
themselves to the condition, we would not care to say.

[Illustration: FIG. 133.--OS PEDIS SHOWING THE GROOVE IN IT CAUSED BY
ATROPHY AND ABSORPTION INDUCED BY PRESSURE OF A KERAPHYLLOCELE.]

Other writers advocate the removal of that portion of the wall to which the
tumour is attached, after the manner described on p. 182, and illustrated
in Fig. 98. This, however, should be a last resource, and should be adopted
only when weighty reasons, such as excessive and otherwise incurable
lameness, appear to demand it.

4. KERATOMA.

In our nomenclature the terms 'Keratoma' and 'Keraphyllocele' are both used
to indicate the condition we have just described. There are some, however,
who reserve the term 'Keratoma' for horny tumours occurring only on the
sole, and for that reason we draw special attention to the word here.
Keratoma may thus be used to describe what we have called keraphyllocele
directly that growth makes its appearance at the sole, and is there able
to be cut with the knife. Similar hard and condensed growths may, however,
make their appearance on the sole in other positions quite removed from the
white line, plainly being secreted by the villous tissue of the sensitive
sole, and having no connection whatever with the sensitive laminae.
They appear as circular patches, varying in size from a shilling to a
two-shilling piece. Compared with the surrounding horn, they stand out
white and glistening, while in structure they are dense and hard, and
offer a certain amount of resistance to the knife. They are of quite minor
importance, and, beyond keeping them well pared down, need no attention.
Keratoma probably offers us the best analogy we have to corn of the human
subject.

5. THRUSH.

_Definition_.--A disease of the frog characterized by a discharge from it
of a black and offensive pus, and accompanied by more or less wasting of
the organ.

_Causes_.--The primary cause of this affection is doubtless the infection
of the horn, and later the sensitive structures, with matter from the
ground. Those factors, therefore, leading to deterioration of the horn, and
so exposing it to infection, may be considered here. Such will be changes
from excessive dampness to dryness, or _vice versa_; work upon hard and
stony roads; prolonged standing in the accumulated wet and filth of
insanitary stables, or long standing upon a bedding which, although dry, is
of unsuitable material.

In this latter connection may be mentioned the harm resulting from the use
of certain varieties of moss litter. This we find pointed out by J. Roalfe
Cox, F.R.C.V.S.[A] Tenderness in the foot was first noticed, and, on
examination, the horn of the sole and of the frog was found to be
peculiarly softened. It afforded a yielding sensation to the finger, not
unlike that which is imparted by indiarubber, and on cutting the altered
horn it was almost as easily sliced as cheese-rind. The outer surface
being in this way slightly pared off, the deeper substance of the horn was
discoloured by a pinkish stain. The horn of the frog was in many instances
found detaching from the vascular surface, which was very disposed to take
on a diseased action, somewhat allied to canker, and became extremely
difficult to treat.

[Footnote A: _Veterinary Journal_, vol. xvi., p. 243.]

Conditions such as these, although not constituting the disease itself,
certainly lay the frog open to infection, especially if afterwards the
animal is called upon to work in the mud of the streets of a large town, or
to stand in a badly drained and damp stable.

A further cause of thrush is to be found in the condition of the frog,
brought about by contraction of the heels (see p. 118). We have already
seen that one of the most prominent factors in the causation of contraction
is the removal of the frog from the ground by shoeing, with its consequent
diminution in size and deterioration in quality of horn. This leads to
fissures in the horny covering, and favours infection of the sensitive
structures beneath. Thrush is, in fact, nearly always present in the later
stages of contracted foot.

By some thrush is believed to be but the commencement of canker. With this,
however, we do not hold. We believe both to be due to specific causes as
yet undiscovered, but that the cause of thrush is not the one operating in
canker. In arriving at this conclusion we are guided by clinical evidence.
The two conditions are quite dissimilar, even in appearance, and, while
one is readily amenable to treatment, the other is just as obstinately
resistant.

_Symptoms_.--The symptoms of thrush are always very evident. Probably the
first thing that draws one's attention to it is the stench of the puriform
discharge. The foot is then picked up and the characteristic putrescent
matter found to be accumulated in the median, and often in the lateral,
lacunae. The organ is wasted and fissured, the horn in the depths of the
lacunae softened and easily detachable, and portions of the sensitive frog
often laid bare.

With a bad thrush lameness is present, the frog itself is tender to
pressure, and often there is considerable heat and tenderness of the heels
and the coronet immediately above. More especially is this noticeable after
a journey.

It is, perhaps, more common in the hind-feet than in the fore, and more
often met with in heavy draught animals than in nags. The hind-feet are, of
course, more open to infection by reason of their being constantly called
upon to stand in the animal discharges in the rear of stable standings,
while it is a well-known fact that heavy animals have their stables kept
far less clean, and their feet less assiduously cared for, than do animals
of a lighter type.

In a nag-horse with thrush of both fore-feet lameness becomes sometimes
very great. The gait when first moved out from the stable is feeling
and suggestive of corns, while progress on a road with loose stones is
sometimes positively dangerous to the driver.

_Treatment_.--When this condition has arisen, as it often does, from want
of counter-pressure of the frog with the ground, this pressure must be
restored after the manner described when dealing with the treatment of
contracted foot (see p. 125) either by the use of tip or bar shoes, or by
suitable pads and stopping.

So far as direct treatment of the lesion itself is concerned, the first
step is to carefully trim away all diseased horn and freely open up the
lacunae in which the discharge has accumulated. Good results are then often
arrived at by poulticing, afterwards followed up by suitable antiseptic
dressings. With us a favourite one is the Sol. Hydrarg. Perchlor. of Tuson,
used without dilution. Others use a dry dressing, and dust with Calomel,
with a mixture of Sulphate of Copper, Sulphate of Zinc and Alum, or with
Subacetate of Copper and Tannin.

With restoration, so far as is possible, of the frog functions, and with
careful dressing, a cure is nearly always obtained.

6. CANKER.

_Definition_.--Under this unscientific, yet expressive term, is indicated a
chronic diseased condition of the keratogenous membrane, commencing always
at the frog, and slowly extending to the sole and wall, characterized by a
loss of normal function of the horn secreting cells, and the discharge of a
serous exudate in the place of normal horn.

_Causes_.--The exact cause of canker has still to be discovered. Therefore,
before expressing an opinion as to what the _probable_ cause may be, we may
state here that such opinion can only be based upon clinical observation.
Such being the case, we are almost duty bound to give the views of older
authors before those of more modern writers.

From the mass of material ready to hand we may select the following as
serving our purpose.

The earliest opinion appears to have been that canker, as the name
indicates, was of a cancerous or cancroid nature. This was also believed by
Hurtrel D'Arboval, who looked upon canker as carcinoma of the recticular
structure of the foot. The same theory we find enunciated in the
_Veterinary Journal_ so late as 1890. Although the word 'cancer' or
'carcinoma' is not there used, the author employs the terms 'Papilloma' and
'Epithelioma' with the evident intention of expressing his belief in the
malignant nature of the disease.

Another early opinion was that the disease was a _spreading ulcer_,
gradually extending and changing the tissues which it invaded.

A further early theory, and one which if not still believed in, has died a
hard death, is the constitutional theory. This was believed in by nearly
all the older writers, and is mentioned so late as 1872 by the late
Professor Williams. In his 'Principles and Practice of Veterinary Surgery,'
he says: 'Canker is a constitutional disease due to a cachexia or habit
of body, grossness of constitution, and lymphatic temperament.' This, we
believe, is credited to-day by some, and yet, quite 100 years before the
date of the 1872 edition of Williams's work--in 1756, to be exact--we find
a veterinary writer when talking of grease (a disease, by-the-by, very
closely allied to canker) exclaiming against this habit of referring
everything which we do not rightly understand to some ill-humour of the
body. The wisdom his words contain justifies us in giving them mention
here. 'It is a very foolish and absurd Notion,' he says, 'to imagine a
Horse full of Humours when he happens to be troubled with the Grease. But
such Shallow Reasoning will always abound while Peoples' Judgments are
always superficial. Therefore, to convince such unthinking Folks, let them
take a thick Stick and beat a Horse soundly upon his Legs so that they
bruise them in several Places, after which they will swell, I dare say,
and yet be in no danger of Greasing. Now, pray, what were these offending
Humours doing before the Bruises given by the Stick?'

At the present day it is safe to assert that neither the ulcerative, the
cancerous, nor the constitutional theory is believed in widely, and, among
the mass of contrary opinions as to the cause of this disease, we may find
that even quite early many of the older writers had discarded them.

Quoting from Zundel, we may say that Dupuy in 1827 considered canker as
a hypertrophy of the fibres of the hoof, admitting at the same time that
these fibres were softened by an altered secretion; while Mercier in 1841
stated that canker was nothing more than a chronic inflammation of the
reticular tissue of the foot, characterized by diseased secretions of this
apparatus.

Saving that they make no mention of a likely specific cause, these last two
statements express all that we believe to-day. As early as 1851, however,
the existence of a specific cause was hinted at by Blaine in his
'Veterinary Art.' We find him here describing canker as a _fungoid_
excrescence, exuding a thin and offensive discharge, which _inoculates_ the
soft parts within its reach, particularly the sensitive frog and sole, and
destroys their connections with the horny covering.

The use of the word 'fungoid,' and particularly that of 'inoculate,' is
suggestive enough, and is evidence sufficient that either Blaine or his
editor recognised, simply through clinical observation, the working of a
special cause.

Four years later, Bouley is found holding the opinion that canker was
closely allied to tetter, thus recognising for it a local specific cause.
The same observer also pointed out that the secretion of the keratogenous
membrane instead of being suspended was greatly increased, taking care to
explain, as did Dupuy, that the products of the secretion were perverted
and had lost their normal ability to become transformed into compact horn.

In 1864 this slowly growing recognition of a specific cause received
further impetus from the statements of Megnier. This observer claimed to
have discovered in the cankerous secretions the existence of a vegetable
parasite (namely, a cryptogam, as in favus), which he termed the
keraphyton, or parasitic plant of the horn.

Modern research, though failing to substitute anything more definite, has
not confirmed this. The exact and exciting cause of canker is therefore
still an open question, and a matter for research. We may, however, sum the
matter up by briefly discussing the causes, so far as clinical observation
teaches us. This we shall do under two headings--namely, _Predisposing_ and
_Exciting_.

_Predisposing Causes_.--Starting with the assumption that the disease is
due to local infection, we may relate as predisposing causes anything
having a prejudicial effect upon the horn, disintegrating it, and so laying
the tissues beneath open to attack. The most prominent in this connection
is certainly a continued dampness of the material on which the animal
has to stand. Particularly is this the case when the material is also
excessively foul and dirty, contaminated with the animal discharges, and
presumably swarming with the lower forms of animal and plant life. We
shall therefore find bad cases of canker in stables where the "sets" are
irregular, or where no paving at all is attempted, where the drainage
is defective, and where darkness and want of proper ventilation favours
organismal growth. The fact that with modern drainage and a general
hygienic improvement in stabling, canker has to a large extent died out,
supports this contention.

Again, as with thrush, anything removing the counter-pressure of the frog
with the ground and throwing that organ out of play, may be looked upon
as a predisposing cause. The atrophy of the frog thus occurring, the
deterioration in the quality of its horn and the fissures in its surface
lay it specially open to infection. That one of the principal factors in
the treatment of canker is a restoration of ground-pressure to the frog and
the sole is sufficient proof of this.



 


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