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.

Although occurring in this way with an acute attack of laminitis, it must
be remembered that seedy-toe may arise without previous noticeable cause.
The first intimation the owner has is a report from the forge that
seedy-toe is in existence. To refer to cases so arising a probable cause is
far from easy. At one time it was believed to be due to parasitic infection
of the horn. Others have blamed the pressure of the toe-clip, excessive
hammering of the wall, or pressure from nails too large or driven too
close. Others, again, say that seedy-toe may result from a prick in the
forge, from hot-fitting of the shoe, from standing on a dry and sandy soil,
or from the use of