If these measures alone should prove insufficient, then the surgeon will either fall back on those we have just related, or proceed to methods next to be described.

(b) Immobilizing the Crack by Means of grooving the Wall.—­To our minds, this is as ready and withal as successful a method of dealing with sand-crack as has yet been devised.  It may be done in a variety of ways:  (1) By two grooves arranged about the crack in the form of a V, as Fig. 94; (2) by a perpendicular groove on either side of the crack, about 1 inch in distance from it, and parallel with the horn fibres, as Fig. 95; (3) by a single horizontal groove at the extreme upper limit of the crack; (4) by drawing two horizontal grooves, one at its upper and one at its lower end (see Fig. 96).

[Illustration:  FIG. 94, FIG. 95, FIG. 96.  In Figs. 94, 95, and 96 the thick black lines illustrate the positions of the various grooves made with the firing-iron for the purpose of immobilizing a quarter sand-crack.]

The points to be observed in carrying out this line of treatment are simple enough.  In all cases see that the crack is rendered as clean as possible by the use of suitable dressings, and if an excess of horn is present immediately around it, as in the case of a long-standing and complicated lesion, have it thinned down by rasping.

All that is then needed is one or two moderately sharp, flat firing-irons.  The groove is then burned into the horn in the positions indicated, and that portion of the wall containing the sand-crack thus prevented from participating in the movements of the foot.  For our own part, we consider the V-shaped incision, or either of the horizontal methods of grooving, preferable to lines running in the direction of the horn fibres.  With the latter there is certainly a greater tendency to the formation of new cracks than with either of those we advocate.  The V-shaped incision we consider most suitable of all, for the reason that by its means a greater degree of immobility is conferred upon the necessary portion of the wall.

Whichever method is adopted, care should be taken to carry the grooves deep enough into the horn, taking them down as near as possible to the sensitive structures.  At the same time, especial care should be exercised in not carrying them too deep at their extreme upper limit, or in that case the liability to the formation of fresh cracks in those positions will be greatly increased.

After grooving, a sharp blister should be applied to the coronet every three or four weeks, and the animal, if free from lameness, put to work.

(c) By stripping away a V-shaped Portion of the Wall around the Crack.—­This method is only indicated when the crack is greatly complicated by the presence of pus, or by the growth of adventitious horn on the inner surface of the wall.  A radical cure is thus obtained, but the animal for a longer time incapacitated from work.