[Ill.u.s.tration: FIG. 41.--THE NEAR HIND-FOOT SECURED WITH THE SIDE-LINE.]

Here the side-line has formed upon it a loop sufficiently large to form a collar. This is placed round the animal's neck, the free end of the line run round the pastern of the desired foot, and the foot drawn forward, as in Fig. 40.

The loose end of the line is then twisted once or twice round the tight portion, and finally given to an a.s.sistant to hold (see Fig. 41). The foot is thus held from the ground, and violent kicking movements prevented.

Where the operation is a major one, restraint of a distinctly more forcible nature becomes imperative. Many of the more serious operations can most advantageously be performed with the patient secured in some form or other of stock or trevis, and the foot suitably fixed. It is not the good fortune of every veterinary surgeon, however, to be the lucky possessor of one of these useful aids to successful operating. Perforce, he must fall back on casting with the hobbles (Fig. 42).

[Ill.u.s.tration: FIG. 42.--CASTING HOBBLES.]

With the use of these we will a.s.sume our readers to be conversant, and will imagine the animal to be already cast. It remains, then, but to detail the most suitable means for firmly fixing the foot to be operated on.

Here the side-line is again brought into use. Care should previously have been taken when casting to throw the animal so that the portion of the foot to be operated on, whether inside or outside, falls uppermost, and that the buckle of the hobble on that particular foot is placed so that it also is within easy reach when the animal is down.

In the case we are ill.u.s.trating the point of operation was the outside of the near hind coronet. We will, therefore, describe the mode of fixing the near hind-foot upon the cannon of the near fore-limb.

[Ill.u.s.tration: FIG. 43.--PHOTOGRAPH ILl.u.s.tRATING METHOD OF ADJUSTING THE SIDE-LINE PREPARATORY TO FIXING THE HIND-LEG UPON THE FORE.]

The side-line is first adjusted as follows: It is fixed upon the cannon of the near hind-leg (A) by means of its small loop. From there it is pa.s.sed under the forearm of the same limb, over the forearm, under the rope running from A to B; from there over and under the thigh, to be finally brought in front of the thigh, and below the portion of rope running from arm to thigh. The loose end of the side-line is then given to an a.s.sistant standing behind the animal's back, the buckle of the hobble restraining the foot unloosed, and strong but steady traction brought to bear from behind upon the line. The operator should now stand in front of the fore-limbs, and, by placing a hand on the rope pa.s.sing round the arm, prevent the line from slipping below the knee.

By this means the hind-limb is pulled forward until the foot projects beyond the cannon of the front-limb. When that position is reached, the operator grasps the hock firmly with one hand, and, directing the side-line to be slackened, gently slides downward the coils of rope round the arm and thigh until they encircle the cannons of both limbs. The cannon of the hind-limb is firmly lashed to the cannon of the fore, and the foot firmly and securely fixed in the best position for operating (see Fig. 44).

[Ill.u.s.tration: FIG. 44.--PHOTOGRAPH SHOWING THE NEAR HIND-FOOT SECURED UPON THE CANNON OF THE NEAR FORE-LIMB.]

Similarly, with the horse still on his off side, the off hind-limb may be fixed to the near fore, and the near fore and the off fore to the near hind.

With the animal on his near side, we may fix the near hind and the off hind to the off fore, and the off fore and near fore to the near hind.

The points to be remembered in fixing the limbs thus are: (1) The side-line should always commence upon the cannon of the limb to be operated on; (2) it should next pa.s.s under and over (or over and under, it is immaterial which) first the arm and then the thigh, or the thigh and the arm, as the case may be; (3) in every case, whether rounding the thigh and the arm from above or below, the piece of rope completing the round should always finish below that portion preceding it, so that traction upon it from behind the animal's back should tend to keep all portions of it from slipping below the knee and the hock.

With the uppermost fore-limb secured to the hind-limb in the manner we have described, we have the underneath fore-limb suitably exposed for both the higher and lower operations of neurectomy. The position for this operation will be made better still if the lowermost limb (the one to be operated on) is removed from the hobbles and drawn forward by an a.s.sistant by means of a piece of rope fastened to the pastern.

Taking what we have described as a general guide, other modifications of thus securing the foot will suggest themselves to the operator to meet the special requirements of the case with which he is dealing.

Regarding the administration of chloroform, no description of the method is needed here, as it will be found fully detailed in most good works on general surgery. Where great immobility is needed, it is one of the most valuable means of restraint we have. Apart from that, its use in any serious operation is always to be advocated, if only on the score of humane consideration for the dumb animal helpless under our hands.

B. INSTRUMENTS REQUIRED.

In addition to those required for operations on the softer structures--such as scalpels, forceps, artery forceps, directors, scissors, etc.--the surgery of the foot demands instruments specially adapted for dealing with the horn.

A great deal will depend upon the operator as to whether these are few or many. The average man of resource will deem a smith's rasp and one or two strong drawing-knives amply sufficient, and on no account should they be omitted from the list of those ready to hand.

[Ill.u.s.tration: FIG. 45.--THE ORDINARY DRAWING-KNIFE.]

The ordinary smith's drawing-knife (Fig. 45) is well known to almost everyone, and is well suited for much of the rougher part of the work.

The careful following up of p.r.i.c.ks, however, and some of the more special operations demanding removal of portions of the lateral cartilages call for instruments of a more delicate character and peculiar construction. These are to be found in the so-called sage-knife, and the modern (French) pattern of drawing-knife.

[Ill.u.s.tration: FIG. 46. _a, b_, Modern forms of drawing-knife; _c, d, e_, sage-knives.]

The modern drawing-knife differs from the smith's instrument in being attached to a straight, instead of a curved, handle, and in usually being sharp on both edges instead of only on one. These are made in various sizes (Fig. 46, _a, b_), and the blades flat, curved on the flat, or curved at an angle with the edges of the haft.

The sage-knife, as its name indicates, is a knife with a lanceolate-shaped blade. These also may be obtained in varying forms and sizes (Fig. 46, _c, d, e_). Fig. 46, _c_, is a single-edged, right-handed sage-knife. Fig.

46, _d_, is a left-handed instrument of the same type. The double-edged sage-knife is represented in Fig. 46, _e_.

[Ill.u.s.tration: FIG. 47.--SYMES'S ABSCESS-KNIFE.]

It may be mentioned too, in pa.s.sing, that the ordinary Symes's abscess-knife (Fig. 47) is a most useful instrument when performing the operation of partial excision of the lateral cartilages, its peculiar shape lending itself admirably to the niceties of the operation.

One or two good-shaped firing-irons will also be found useful. They will lighten the labour of tediously excavating grooves with the knife, where that procedure is necessary; and, used in certain positions to be afterwards described, will afford just that necessary degree of stimulus to the horn-secreting structures of the foot, which the use of the knife alone will not.

The man in country practice will also be well advised in carrying to every foot case a compact outfit, such as that carried by the smith. This will consist of hammer and pincers, drawing-knife and buffer. Much valuable time is then often saved which would otherwise be wasted in driving round for the nearest smith.

There are other special operations requiring the use of specially-devised instruments for their successful carrying out. These we shall mention when we come to a consideration of the operations in which they are necessary.

C. THE APPLICATION OF DRESSINGS.

One of the most common methods of applying a dressing to the foot is poulticing. Usually resorted to on account of its warmth-retaining properties, the poultice may also be medicated. In fact, a poultice, strongly impregnated with perchloride of mercury or other powerful antiseptic, is a useful dressing in a case of a punctured foot, or a wise preliminary to an operation involving the wounding of the deeper structures. The poultice may consist of any material that serves to retain heat for the longest time. Meal of any kind that contains a fair percentage of oil is suitable. Crushed linseed, linseed and bran, or linseed-cake dust are among the best.

To prepare it, all that is necessary is to partly fill a bucket with the material and pour upon it boiling water. The hot ma.s.s is emptied into a suitable bag, at the bottom of which it is wise to first place a thin layer of straw, in order to prevent the bag wearing through, and then secured round the foot. This is generally done by means of a piece of stout cord, or by straps and buckles fastened round the pastern and above the fetlock.

An improved method of fastening has been devised by Lieutenant-Colonel Nunn:

'A thin rope or stout piece of cord about 5 feet long is doubled in two, and a knot tied at the double end so as to form a loop about 5 or 6 inches long, this length depending on the size of the foot (as at A, Fig. 48). The poultice or other dressing is applied to the foot, and the cloth wrapped round in the ordinary way, the loop of the cord being placed at the back of the pastern (as in A, Fig. 49); the ends of the cord are pa.s.sed round, one on the inside and the other on the outside, towards the front (as in B, Fig. 49). These ends are then twined together down as far as the toe (see C in Fig. 49). The foot is now lifted up, and the ends of the cord (CC, Fig.

49), are pa.s.sed through the loop A (as at D, Fig. 49), and then drawn tight. The ends of the cord are now separated, and carried up to the coronet (as at EE, Fig. 49), one on the outside, the other on the inside of the foot. They are then again twisted round each other once or twice (as at F, Fig. 50), and are pa.s.sed round the pastern once or twice on each side.

They are now pa.s.sed under the cord (E, Fig. 49), and then reversed, so as to tighten up E, and are finally tied round the pastern in the usual manner. The arrangement of the cords on the sole is shown in Fig. 51, which is a view from the posterior part.

[Ill.u.s.tration: FIGS. 48, 49, 50, 51.--ILl.u.s.tRATING LIEUTENANT-COLONEL NUNN'S METHOD OF APPLYING A POULTICE TO THE FOOT.]

'The advantages of this method of fastening have been found to be: (1) It does not chafe the skin; (2) if properly applied it has never been known to come undone; (3) it is the only way we know that a poultice can be satisfactorily applied to a mule's hind-foot; (4) horses can be exercised when the poultice is on the foot, which is almost impossible with the ordinary leather boot; (5) the sacking or canvas does not cut through so quickly.'

[Ill.u.s.tration: FIGS. 52, 53.--TWO FORMS OF POULTICE-BOOT.]

A further method of applying the poultice is by using one of the poultice-boots made for that purpose (see Figs. 52 and 53).

These have an objection. They are apt to be allowed to get extremely dirty, and so, by carrying infective matter from the foot of one animal to that of another, undo the good that the warmth of the poultice is bringing about.

The advantage of the ordinary sacking or canvas is that it may be cast aside after the application of each poultice. Where the boot is kept clean, however, it will save a great deal of time and trouble to the attendant.

While on the subject of poulticing, it is well to remark that in many cases it may be more advantageous to supply the necessary warmth and moisture to the foot by keeping it immersed in a narrow tub of water maintained at the required temperature. By this means the warmth is carried further up the limb (sometimes an important point), and the water can more conveniently be medicated with whatever is required than can the poultice. In fact, it is the author's general practice, where the attendants can be induced to take the necessary pains, to always advise this latter method.

[Ill.u.s.tration: FIG. 54.--SWAB FOR APPLYING MOISTURE TO THE FOOT.]

Where a dressing is relied upon by some pract.i.tioners on account of the warmth it gives, others, even in identical cases, will depend upon the effects of cold. This may be applied by means of what are called 'swabs.'

In their simplest form swabs may consist only of hay-bands or several layers of thick bandage bound round the foot and coronet, and kept cool by having water constantly poured upon them. In many cases the form of swab depicted in Fig. 54 will be found more convenient.

When only one foot is required to be dressed, and a water-supply is available, by far the preferable method is to attach one end of a length of rubber tubing to the water-tap, and fasten the other just above the coronet, allowing the water to trickle slowly over the foot. In cases where a forced water-supply is un.o.btainable, and the case warrants the extra trouble, much may be done with a medium-sized cask of water placed somewhere over the animal, and the rubber tubing connected with that.

Where the dressing is desired to be kept applied to the sole and frog only, there is no method more satisfactory than the shoe with plates.