336 DISEASES OF THE HORSE'S FOOT 



the hoof, breaks out at the coronet. Again, too, as with 

 the simpler form of qnittor, and as with coronitis, we may 

 always regard as a predisposing cause the action of exces- 

 sive cold in promoting septic infection of the wound when 

 occurring at the coronet. 



Symjytoms and Diagnosis. — Where the fistulous wound 

 has had its starting-point in an injury to the coronet diag- 

 nosis is, of course, easy. The history of the case explains 

 it. Nothing in this instance remains but to probe the 

 opening, and ascertain its direction, depth, and extent. 



An animal with the wound thus open at the coronet, and 

 freely discharging its contents, may, if no serious com- 

 plications exist, walk tolerably sound. It is only when put 

 to the trot that symptoms of lameness are apparent. 



It may so happen, however, that we first see the case 

 when the symptoms are wholly those arising from a painful 

 suppuration within the horny box. This occurs when the 

 original injury has taken place at a more dependent posi- 

 tion than the coronet. Either from violent blows upon the 

 hoof, puncture from below, from corn or from sand-crack, 

 or any other causes we have enumerated, suppuration is 

 occurring deeply within the hoof, with as yet no opening 

 upon the coronet. 



Even when an opening has already occurred on the 

 coronet, the same condition of sub-horny suppuration may 

 be met with in cases when the opening of the fistula has by 

 some means or other become occluded. Granulation tissue, 

 for instance, may have temporarily closed the mouth of 

 the fistula. The pus, instead of continuing its discharge 

 thereat, is made to burrow in other directions. 



In either of these cases pain is excessive, the animal 

 walks on three legs, the foot is painful to percussion, and 

 grave constitutional disturbance is noticeable. The pre- 

 sence of pus is immediately suspected, and, in the absence 

 of any indication of an opening having existed at the 

 coronet, searched for at the sole. It may or may not be 

 found. If found it is given exit, and the case ends as one 

 of ordinary pricked foot, of suppurating corn, or some other 



