102 The Diseases of Animals 
Tn most cases cracks in the walls of the hoof are 
due to a dry, weakened condition of the walls. Severe 
exertion, especially fast work on hard roads, tends to 
split the hoof. Cracks may also be caused by an injury 
to the coronet, where the horny wall is secreted; this 
interferes with the growth of horn, and a crack results. 
Excessive growth of the wall in unshod horses may 
cause cracks. 
(Quarter-crack may cause severe lameness. The hoof 
spreads as the animal steps on it and the soft tissues 
are often pinched in the crack as the foot is picked up 
and the crack closes, thus causing 
the parts to bleed. Sand and 
gravel may get into the crack and 
eause trouble, or “proud flesh” may 
form that interferes with the heal- 
ing. In some cases there is no 
lameness, and unscrupulous horse- 
: traders sometimes hide the cracks 
Fig. 25. Quarter-crack by filling with soap, in order to 
closed by nails. _ 
dispose of the horse. 
The crack is to be neatly cleaned out; if “proud flesh” 
exists, it is to be destroyed with a caustic, antiseptics 
applied to the crack, and then pine tar, to keep out dirt 
and assist in healing. The erack should be drawn 
together by a shoeing nail driven across the erack, 
drawn tightly together and clinched (Fig. 25). It may 
be necessary to drill the holes for the nails, but in most 
cases a good shoeing smith can drive them. Small clips 
are made for this purpose, which can be fitted into 
grooves on each side of the erack, and closed by large 
ih 
Hse 1 
hie f 
a 
= 
