234 DISEASES OF THE HORSE'S FOOT 
calkin of the opposite foot. Where a wound in this posi- 
tion is characterized by an excessive flow of synovia, the 
condition should be suspected, and, if the wound be large 
enough, the little finger should be introduced in order to 
ascertain. Needless to say, the injury is a grave one. 
(e) Sand-crack.—Sand-crack is likely to result from tread 
when an injury is inflicted in the region of the quarter by a 
severe overreach. Treads, too, especially with the calkin 
of the hind-shoe, are especially apt to end in this way. In 
this latter instance the sand-crack usually has its origin 
in a nasty jagged tear at the top of the wall of the toe. 
(f) Quittor.—In one respect any suppurating wound at 
the coronet may be deemed a quittor. By indicating quittor 
as a complication of coronitis, however, we denote the 
more serious form of this disease, in which the wound has 
taken on a sinuous character, and conducted pus to invasion 
of the lateral cartilage. It is one of the worst complica- 
tions we are likely to meet with in this condition, and will 
be found fully described in Chapter X. 
(g) False Quarter.—This complication of coronitis occurs 
when the injury or after-effect of the formation of pus has 
been severe enough to destroy outright a comparatively 
large portion of the papillary layer of the coronary cushion. 
To this condition we devote Section D of this chapter. 
Prognosis.—In giving a prognosis in a case of coronitis, 
attention should be paid to the manner in which the condi- 
tion originated, and the extent, when present, of the wound. 
When the inflammatory swelling has arisen from bruis- 
ing alone, without actual division of the skin, when the 
weather is that of winter, and the swelling showing a 
marked tendency to spread, then the prognosis must be 
guarded. As we have seen, this state of affairs is probably 
ushering in a condition of spreading suppuration of the 
coronary cushion, and considerable gangrene and slough- 
ing of the skin. We have here no intimation as yet of 
how far the suppurative process may run, nor what im- 
portant structures it may involve. Consequently, the 
guarded prognosis we have mentioned is imperative. 
