Diseases of the Horse's Foot Part 37

Finally, numerous small and lightly-rolled b.a.l.l.s of dry carbolized tow are packed regularly over the whole of the operation wound, and the foot bandaged.

Practical points to be remembered in this after-dressing are: (1) The b.a.l.l.s[A] of tow should be numerous enough to exercise pressure upon the sutured flap when the foot is finally bandaged. (2) The bandage should be run on from the coronet downwards, in order to insure pressure being exerted in the exact position over the sutured flap. (3) Bandages should be used in abundance, commencing always from the coronet, and carefully applied so as to exert an even and uniform pressure. (4) The bandages should be of clean, unused linen.

[Footnote A: Bayer recommends that the tow be rolled into cylindrical tampons, each long enough to cross the wound. These are placed on the wound in alternate horizontal and vertical layers, so that when rolled round by a bandage they are pressed into an even and compact pad.]

Once the bandages are adjusted, the hobbles may be removed, and the tourniquet loosened. Directly the tourniquet is removed there is a steady oozing of blood through the bandages, no matter how many we have put on.

This should occasion no alarm, as experience has taught that the careful attention to antiseptic measures observed throughout the operation has the effect of maintaining the lowermost dressings, those next to the wound, in a state of asepsis. The bandaged foot should now be wrapped in a piece of thick clean cloth or placed in a boot.

If our antiseptic precautions have been thorough, the dressings and bandages so adjusted may be allowed to remain without disturbance for from eight to fourteen days. In this, however, the veterinary surgeon must be largely guided by the symptoms of his patient. If, at the end of the first three or four days, the animal maintains a vigorous appet.i.te, if he commences to place a little weight on the foot, and if the thermometer gives no indication of a rise beyond the one or two degrees of ordinary surgical fever, then the surgeon may know that things are proceeding satisfactorily. Pawing movements with the foot, inability to place weight upon it, loss of appet.i.te, an increase in the number of respirations, and a serious rise of temperature, denote the opposite state of affairs. The wound is in all probability suppurating. The bandages and dressings should therefore be removed, and the wound either redressed and bandaged, or treated as an ordinary open wound.

Ordinarily, however, if the operation has been properly performed, healing takes place by first intention, and the wound when the bandages are removed at the end of the first or second week appears clean and _dry_.

Having a.s.sured ourselves that such is the case, we dress the foot in exactly the same manner as before, save that so many bandages are not put on. A similar dressing is repeated weekly until such time as the wound shows sufficient growth of horn--quite a thin pellicle--to act as a protective. It may then be left undressed, except for some simple hoof dressing and a bandage.

Complete healing of the wound takes from about four to eight weeks, at the end of which time the animal can be again gradually put into work. The labour, however, should be light, and quite three or four months should be allowed to elapse before any attempt is made to put him to heavy work.

Should the second method of operating have been the one adopted, then there is one slight difference in the after-dressing that needs attention calling to it. In this case we have more or less of a _hidden_ cavity left to deal with rather than the broad and _open_ wound left in either of the other methods. This cavity, left by the extirpation of the cartilage, must be thoroughly dressed with iodoform or chinosol, or with Bayer's iodoform in ether. The packing with carbolized tow and the bandaging may then be proceeded with as before.

In conclusion, we may say that the operation is one of some delicacy, and needs a good surgeon for its successful performance. Furthermore, no one of the antiseptic precautions we have advised can be omitted. It is, perhaps, these two considerations (and in justice to the English surgeon we should say most probably the latter of them) that have prevented this operation from being generally adopted.

That it is successful there is no gainsaying. Professor Bayer, of the Vienna School, with whose name is a.s.sociated the last of the three methods of operating we have described, is enthusiastic in praise of the operation, and says: 'The favourable results that I have got by this operation have caused me wholly to abandon the medicinal treatment, and to prefer in all cases the surgical operation as being the best means to the end.'

_Partial Excision of the Lateral Cartilage_.--Discarding the somewhat elaborate methods we have just described, there are English operators who removed the necrosed portion only of the cartilage, and do so in what appears at first sight a comparatively rough-and-ready manner.

The apparent roughness is that they do not concern themselves with conserving the coronary cushion, and hesitate but little in cutting portions of it bodily away. One would imagine that in this case the quarter of the side operated on would be always more or less bare of horn. Such, however, is not the case.

To perform this operation the animal is again cast and chloroformed. Some operators, however, use the stocks and dispense with the anaesthetic. The foot is first well cleaned with soap and water and a stiff brush, and the hair of the coronet over the seat of operation shaved. Again, too, the horn of the affected quarter is rasped until it yields easily to pressure of the thumb, and the whole of the foot washed in an antiseptic solution.

A probe is now inserted into the opening at the coronet, and the direction of the fistula noted, after which the foot is firmly secured, and an Esmarch bandage and tourniquet applied to the limb.

This done, a triangular or wedge-shaped portion of skin, coronary cushion, and thinned horn is removed with a strong sage-knife or scalpel.

The base of the wedge-shaped portion removed contains the opening of the fistula, and the apex of the wedge should reach to the bottom of the sinus (see Fig. 142).

After the horn is removed and the fistula followed up, it is sometimes found that what we at first thought was its end, it may now be continued in an altogether different direction.

It is again followed up with the probe, and the horn and sensitive structures excised until we are quite certain we have reached its furthest extent.

Attention should next be paid to the cartilage. Wherever spots of necrosis are found, as indicated by the pea-green colour of the affected parts, they must be _carefully_ excised. Care should be taken in so doing to carry the line of excision some little distance around the visibly affected parts.

This is done that we may be quite certain nothing at all remains calculated to give rise to further trouble.

It goes without saying that, in addition to the necrosed cartilage, all other diseased and necrotic tissues should also be removed. The os pedis is occasionally found necrotic just where the cartilage joins it, or it may be that a small portion of the sensitive laminae, by reason of its _liver-red_ or even gray coloration, gives evidence of death of the part.

The former must be well curetted, and the latter cleaned carefully with a scalpel and forceps.

[Ill.u.s.tration: FIG. 142.--PARTIAL EXCISION OF THE LATERAL CARTILAGE BY REMOVING A PORTION OF THE CORONARY CUSHION. The dotted lines show the outline of the wedge-shaped portion of structures to be removed, including skin, coronary cushion, horn, and sensitive laminae. _a_, The opening of the fistula.]

The operation finished, the foot is again douched in an antiseptic solution, the wound mopped dry with carbolized tow, dressed with either of the dressings described on page 358, and finally bandaged. The dressing should be changed every three days only, unless in the meanwhile pawing movements and other symptoms of distress indicate their removal.

The length of coronary cushion removed in this operation is from 1/4 to 1/2 inch (we ourselves, however, have seen it more), and yet its loss seems to occasion no serious after-trouble beyond a slight deformity of the parts beneath. The sensitive structures become sufficiently covered with horn, and the animal in nearly every case is returned to work, while in a great many instances he may also trot perfectly sound.

Simple though the operation may appear, and apparently rough in its method, it is nevertheless successful in effecting a cure in cases where blisters, plugging, injections, and other means have failed.

Mr. W. Dacre, M.R.C.V.S.,[A] after reading an article on the operation before the members of the Lancashire Veterinary Medical a.s.sociation, says: 'My observations have not been based on a single case, and having had nine of them, and all of them successful, I felt it to be my duty to bring this subject before the Society.'

[Footnote A: _Veterinary Record_, vol. v., p. 407.]

Mr. T.W. Thompson, M.R.C.V.S.,[A] says: 'In a great number of cases I have removed a 1/2 inch of the coronary band.... I have performed the operation a great number of times, and have never seen a foot that has been damaged by it.'

[Footnote A: _Ibid_.]

Professor Macqueen[A] says: 'I do not spare the coronary band or sensitive laminae when I find those parts diseased. I do not unnecessarily damage those structures. At the same time, I am confident that excision of a piece of the coronary band or removal of a few sensitive laminae has not the untoward consequences so much dreaded in former days.'

[Footnote A: _Ibid_., p. 714.]

Mr. John Davidson, M.E.C.V.S.,[A] says: 'The treatment described, if carefully carried out and details attended to, will be found a success in dealing with the majority of cases of quittor. If I may be permitted to say so, without being considered boastful, I have yet to see the first case that has resisted the treatment.'

[Footnote A: _Ibid_., vol. xiv., p. 769.]

Should our case of quittor be complicated by caries of the bone, this must, where possible, be sc.r.a.ped or curetted until the whole of the diseased portion is removed, and a healthy surface is left. After-dressing must then be carried out as in other cases.

The treatment of ossified cartilage will be found under treatment of side-bones, and the methods of dealing with penetrated articulation and purulent arthritis are treated of in Chapter XII.

_Surgical Shoeing in Quittor_.--In the case of simple or cutaneous quittor, no alteration in the shoeing is necessary.

When the condition becomes sub-h.o.r.n.y, however, and particularly when it is situated in the region of the quarters, ease is afforded to the diseased parts by removing the bearing of the shoe in that position.

Should there be no dependent opening at the sole, then the best shoe for the purpose is an ordinary bar shoe (Fig. 68), with the bearing eased under the affected quarter.

If, however, there is a dependent orifice, or one is expected, then it will be necessary either to leave the animal unshod or to provide him with a shoe that admits of dressing the lesion. In the latter case the most suitable shoe will be found to be either a three-quarter shoe (Fig. 102) or a three-quarter bar shoe (Fig. 103). Many operators, however, keep the animal unshod. We must say ourselves that we consider a shoe useful after either of the operations for removal of the cartilage, if only to a.s.sist in maintaining the bandages and dressings in position.

In this case a very useful shoe will be the three-quarter bar shoe. With a little manipulation the bandages are easily run under the bar portion of the shoe, and a few of their turns every now and again wrapped round the bar in order to keep the whole firmly in position.

In connection with tendinous quittor, when septic matter has gained the sheath of the flexor tendons, there is, for a long time after healing of the fistula, a marked tendency for the animal to go on his toe. To a large extent we judge this to be due to slight adhesions between the two tendons brought about by the growth of inflammatory fibrous tissue. In such cases benefit is sometimes derived from the application of a shoe with an extended toe-piece (see Figs. 84 and 108).

C. OSSIFICATION OF THE LATERAL CARTILAGES, OR SIDE-BONES.

_Definition_.--An abnormal condition of the lateral cartilages, in which the substance of the cartilage becomes gradually removed and bone formed in its place.

[Ill.u.s.tration: FIG. 143.--OSSIFIED LATERAL CARTILAGES (SIDE-BONES).]

_Symptoms and Diagnosis_.--Side-bones are nearly always met with in heavy draught animals, and are rarely seen in the feet of nags. They are, moreover, nearly always confined to the fore-feet. In the ordinary way little need be said concerning their characteristics, and the way in which they may be detected. Neither need any concern be ordinarily manifested with regard to the effect they may have on the animal's gait and future usefulness. Seeing, however, that side-bone const.i.tutes one of the recognised hereditary diseases, and that at the various agricultural and horse shows its existence or otherwise in a certain animal is a matter of great importance, some little attention must be given to these two points.

With a side-bone anywhere approaching full development, diagnosis is easy.

The thumb is pressed into the coronet over the seat of the cartilage, when, in place of the elasticity we should normally meet with, we have the solid resistance offered by bone. In some instances diagnosis is even easier still. We refer to those cases in which the side-bone stands above the level of the coronet with such prominence as to be readily _seen_ and recognised without manipulation, and where its growth has caused distinct enlargement and bulging of the wall of the affected quarter. It seems that in such cases the bone-forming process does not end with simply depositing bone in place of the removed cartilage, but that, after that is accomplished, the bone still continues to be produced, as in the case of an exostosis elsewhere.

Although diagnosis in cases such as these is easy, it becomes a very different matter when we are called upon to give an opinion in cases where ossification of the cartilage is only just commencing. Whether the result of our examination is to decide the sale or purchase of an animal, to determine his fitness or otherwise to enter the show-ring, or to merely advise a client as to whether or no a side-bone is in course of formation, our position is equally difficult, and in either case our examination must be searching.