'Should subjacent healthy structures be destroyed during the process, that is shown by the production of a raw sore, or of a sore to which a "sit-fast," coextensive to the injury, is firmly attached. This seriously r.e.t.a.r.ds recovery. The secreting surface having been destroyed, no new horn can be produced directly from the part, and a new secreting surface and new horn have now to grow inwards from the surrounding undestroyed tissue, and that is a slow process. At the same time, on the principle of choosing the least of two evils, practical experience teaches that it is better to produce a small sore or a "sit-fast" than to leave a part of the canker undetected; but, on the other hand, it is better to leave a small part of canker undetected, which can be recognised and removed at the next examination, than to cause a large slough. The object of the skilful surgeon is, naturally, to avoid both extremes; and if trouble be taken to carry out the procedure described, there need be no fear of the result.'[A]

[Footnote A: _Journal of Comparative Pathology and Therapeutics_, vol. iv., p. 24.]

Treated in this way, the horse with cankered feet may be usually kept at work during the whole time that treatment is carried out, and a cure is obtainable in periods varying from six weeks to six or even twelve months.

The same essentials in treatment--namely, removal of diseased horn, antiseptic dressings, and pressure--are insisted on by other writers.

Bermbach,[A] in 1888, treats canker as follows: The horse having been cast, the undermined hoof-horn is removed with the knife, and the hypertrophied sensitive structures, if necessary, reduced in the same manner. The chief difficulty in removing the latter is experienced in the lateral lacunae of the frog, where it is most conveniently sc.r.a.ped away with a spoon or sharp curette. Professors Hoffmann and Imminger also operate in the same way, applying an Esmarch's haemostatic bandage, and using the knife and curette freely.[B]

[Footnote A: _Ibid_., vol. ii., p. 68.]

[Footnote B: _Veterinary Journal_, vol. x.x.xv., p. 433.]

Haemorrhage is afterwards arrested, and a dressing of perchloride of mercury (a solution, 1/2 per cent., in equal parts of alcohol and water) applied.

The after-dressings succeeding best are those of _slightly_ caustic and astringent agents, preferably in the form of a powder, and held in position by carbol-jute pads and linen bandages applied with a certain amount of pressure.

The same author draws attention to the fact that caustic agents such as nitrate of lead, chloride of zinc, etc., act too powerfully if the bleeding has been arrested and the wound disinfected. They then form a thick crust, under which profuse suppuration takes place. The same agents are likewise contra-indicated when haemorrhage is still present. In this latter case they combine with the blood to form metallic alb.u.minates, which lie as an impenetrable layer on the surface of the wound, and so hinder the action of drugs on the tissue below.

During his after-treatment, Bermbach advocates removal of the dressings every second day, all cheesy material to be sc.r.a.ped away with the knife, and the sublimate lotion to be used again. He also insists on the animal being kept standing in a _dry stable_,--nothing but a stone pavement kept clean--and put to regular work in a plate shoe after the first or second week. Cure of advanced cases is said to be obtainable in from four to six weeks.

As ill.u.s.trative of the value of pressure in the treatment of canker, we may also draw attention to a treatment advocated by Lieutenant Rose.[A] This observer holds that adequate pressure is un.o.btainable by packing the foot, and, to obtain it, removes the wall from heel to heel, much after the manner of preparing the foot for the Charlier shoe, so that the _whole_ of the weight is taken by the sole and the frog. Tar and tow is then lightly applied, the foot placed in a boot, and the patient turned into a loose-box. The dressing is repeated at intervals of four or five days until the animal is cured.

[Footnote A: _Veterinary Record_, vol. xi., p. 435.]

Those who have followed this method of treatment have modified it by actually shoeing the animal Charlier fashion, and keeping him at work, attention, of course, being at the same time given to a proper antiseptic dressing.

_Reported Cases_.--1. (Malcolm's Treatment[A]). The subject was a five-year old horse belonging to a client of Mr. Giver's, of Tamworth. The case was an exceptionally bad one, for not only was the whole of the frog and sole of the near hind-foot cankered, but the disease on the outside quarter extended to within 1/2 inch of the coronet, and on the inside quarter to within 2 inches of it. As the owner, a farmer, had not proper convenience for Mr. Olver to treat the case, the latter asked me, while visiting him, if I would care to undertake the treatment, saying at the time it would be a very good test-case, as the disease was so far advanced. I readily agreed, and, after the necessary arrangements, had the horse removed to Birmingham on July 2. In this case it was found necessary to cast the animal and cauterize the foot a second time before a healthy granulating surface was secured; but after this the progress towards recovery was uninterrupted, although necessarily slow, on account of the large amount of new secreting surface which had to be formed.

[Footnote A: _Journal of Comparative Pathology and Therapeutics_, vol. v., p. 48.]

The horse was finally discharged, after inspection by Mr. Olver, absolutely cured and free from canker, on January 7.

The ill.u.s.tration (Fig. 135, p. 312) is from a photograph, and it gives a somewhat imperfect representation of the state of the foot two months after it came under my care.

2. (Rose's Treatment.[A]) This was a bad case of canker, which had been for two or three months treated in the ordinary manner, with but little sign of ultimate success. Commenced in June and carried on until the end of September, the ordinary treatment consisted in burning down the fungus growth with the hot iron, and dressing with copper sulphate, zinc sulphate, and boracic acid. The cauterization was repeated every five days.

[Footnote A: _Veterinary Record_, vol. xi., p. 435.]

The treatment of Lieutenant Rose was commenced at about the end of September, at which date the disease extended from the toe on one side of the foot right back to the heel, involving the sole, half of the frog, and the bulb of the heel. One week after treatment the diseased surface was drier, and granulations were more healthy. At the expiration of a fortnight the new horn had commenced to grow from the wall, and also from the frog, right round the diseased surface, the diseased part of the bulb of the heel being divided from the sole by new horn.

Three to four weeks later the diseased surface was gradually getting smaller, while in about six weeks it was quite healed up, the last place to heal being a strip outside the bar, between it and the wall, and a smaller spot on the bulb of the heel. These healed up simultaneously, and left the animal sound.

3. (Treatment by Pressure, H. Leeney [A]). I was consulted in the early part of last summer, before the dry weather had begun, as to a farm-horse with canker in three feet. Her shoes were in the 'disgruntle' condition we so often find on farms, that, to give her a level bearing until I should call another day with a farrier to help me to pack the foot up in the old-fashioned way, I had the remaining shoes pulled off. The case somehow dropped out of my list, and I neglected to call, until asked one day to see something else.

[Footnote A: _Veterinary Records_, vol. xi., p. 447]

I then found that, under a pressure of work, the animal had been used in the shafts of a farm-cart on tolerably level ground, and when the dry weather had already set in. There was a distinct improvement in all the diseased feet, and as she was badly wanted I contented myself with rasping off some broken crust, and supplied some caustic dressing for use at night.

Without shoes she worked continuously on the dry and hard meadow-land for several weeks, and was practically cured in something less than three months. My astringent or caustic lotion may have had something to do with the cure of the deep-seated parts, but the bare recital of the case should be sufficient to show that it is all a question of bearing, or nearly so.

7. SPECIFIC CORONITIS.

_Definition_.--In describing this condition under the above heading, we are following the lead of Mr. Malcolm. We may define it as a chronic inflammatory condition of the keratogenous membrane, usually confined to that of the coronary cushion, the ergots and the chestnuts, but sometimes extending to that of the frog and the sole, characterized by a malsecretion of the affected membrane similar to that observed in canker.

_Causes_.--The cause which we have indicated for canker--namely, a local specific one, is in all probability the one operating here. Apparently there is a variance of opinion as to whether the condition is actually canker or not. We think, however, that the character of the secretion of the affected membranes, the appearance of the growths, the manner in which they react to the hot iron, the comparative absence of pain, and other points of similarity, point to the fact that the two conditions are actually identical. In other words, the cause is precisely the same, and the only point of difference is the alteration in the point of attack.

_Symptoms_.--Like canker, the disease is insidious in onset. In precisely similar manner the horn, and in this case the skin of the coronet, is underrun. Later there is the partial shedding and fissuring of the undermined horn and the exuding of the characteristic discharge--in this case not so watery as that of canker. The caseous material of canker is also present, as is a disposition to hypertrophy of the exposed sensitive structures. What horn is left becomes rough and irregularly fissured, and has been likened by some observers to deeply-wrinkled bark of an old tree.

A peculiar characteristic of this condition is the state of the ergots and chestnuts. Here the keratogenous membrane partic.i.p.ates in the diseased process, and their horn becomes dry and brittle, and readily splits into small fibrous bundles very similar to the fibroid growth described in canker. These excrescences are easily separated from the sensitive structures beneath, and the exposed surface is seen to be more or less moist, or even exhibiting a slight oozing of blood.

Again, as in canker, the deeper layers of the sensitive structures appear to be normal, the horn-secreting layers being the only ones affected.

According to Malcolm, the disease is in its nature equally as inveterate as canker, but it is easier to treat, on account of its more exposed position.

_Treatment_.--This is exactly that as described for canker.

[Ill.u.s.tration: FIG. 137.--SPECIFIC CORONITIS OF ALL FOUR FEET.]

[Ill.u.s.tration: FIG. 138.--OFF FORE-FOOT AFFECTED WITH SPECIFIC CORONITIS.]

_Recorded Case_.--The subject of this case was a young black cart gelding.

The disease is reported as having begun as thrush, and then extended to the coronet. When I saw him he had been in a similar condition to that depicted in Fig. 137 for, it was said, two or three months, the driver of the horse meanwhile endeavouring to effect a cure by some potent drug of his own. The animal was in good condition, but walked with difficulty owing to the pain.

The coronary bands were swollen to two or three times their natural size, and this caused the hair immediately above to curl upwards. Just below the coronary bands there was a line of separation between them and the wall.

They themselves were covered with the cheesy substance typical of canker, and they bled on friction. Down the wall of the off fore-foot some blood had trickled, which may be seen in Fig. 138. The frogs of all four feet bulged backwards, and were badly affected. The soles were covered with normal horn, but I did not resort to paring to see if they were affected.

One very curious feature about the case was the fact that all the callosities (ergots and chestnuts) seemed to partic.i.p.ate in the morbid process, and they, too, were covered with a thin layer of soft cheesy horn.

The animal used to bite at his coronets and also the callosities above the knees and hocks until they bled, which they did quite easily. The owner would not go to the expense of having him treated, so he was destroyed.[A]

[Footnote A: Henry Taylor, _Veterinary Record_, vol. xvii., p. 311.]

CHAPTER X

DISEASES OF THE LATERAL CARTILAGES

A. WOUNDS OF THE CARTILAGES.

To a consideration of this we shall devote but little s.p.a.ce. It is sufficient to say that any wound in the region of the coronet should always be given the most careful attention. More particularly should this be so when it is ascertained that the wound has involved one of the lateral cartilages. Wounds of non-vascular bodies such as these are always slow to heal, and, by reason of their slowness, invite septic infection. In many cases, in fact, it happens that they do not heal at all. Instead, the injured part becomes necrotic, is unable to cast itself off, and remains as a centre of infection in the depths of the wound, thus const.i.tuting what is known as a quittor.

Apart from this, it will be remembered that the internal face of the cartilage is in intimate contact with the pedal articulation, especially anteriorly. Wounds in this situation are, therefore, likely to penetrate the joint, giving us as a complication of the injury the conditions of synovitis and arthritis.

Immediately a wound is inflicted in this position, attempts should be made to insure thorough asepsis of the part. When possible, by far the better way of accomplishing this will be to wholly immerse the foot in a tub of cold antiseptic solution, and keep it there for an hour three times daily.

During the time the foot is out of the solution the wound should be protected with a pad of carbolized tow or other suitable dressing, and wrapped in a linen bandage or clean bag. If unable to use the bath, then antiseptic solutions of more than moderate strength should be freely applied to the wound and the adjacent parts, a carbolized or other antiseptic pad placed over it, and the bandage adjusted as before. Repeated injuries to the cartilages, even if not attended with an actual wound, are apt to bring about their ossification and end in the formation of side-bones.

B. QUITTOR.

_Definition_.--A fistulous wound of the foot, usually opening at the coronet, and variously complicated according to the structures invaded by its contained pus. For the reason that quittor is in every-day veterinary nomenclature _usually_ a.s.sociated with necrosis or other abnormal condition of the lateral cartilage, we include its description in this chapter.

_Cla.s.sification_.--It has been customary with Continental authors to cla.s.sify quittor according to the extent and position of the diseased process. There were thus distinguished:

_(a)_ The _Simple_ or _Cutaneous Quittor_, in which had occurred nothing more than necrosis of a portion of the coronary skin and the structures immediately underlying it--that is, the superficial portion of the coronary cushion.