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.