196 DISEASES OF THE HORSE'S FOOT 



get pressure upon and final gangrene of the sensitive sole 

 and of the sensitive laminae of the bars and the wall. 

 With no outlet below, the pus formation increases until 

 finally it finds its way out of the hoof by emerging at the 

 coronet. 



This in some instances it may do by confining its necrotic 

 influences solely to the sensitive laminae of the wall, in 

 which case, if a dependent orifice is quickly made at the 

 sole, the injury to the laminae is soon repaired by the healthy 

 tissue remaining. 



In other cases, however, the necrosis has spread deeper. 

 Caries of the os pedis, of the lateral ligaments of the pedal- 

 joint, or of the lateral cartilages, is a result. When this 

 occurs the exuding discharge from the coronet becomes 

 thinner and more putrescent, and its feel, when rubbed 

 between the fingers, sometimes gritty with minute frag- 

 ments of broken-up bone. Here, unless operative measures 

 prevent it, necrosis soon spreads deeper still. The deeper 

 portions of the os pedis become affected. The capsular 

 ligament of the joint is penetrated by the suppurative pro- 

 cess, and a condition of septic arthritis results. The cavity 

 of the joint becomes more or less tensely distended, accord- 

 ing to the amount of drainage present, which in this case 

 is almost nil, with matter in a state of putrescence. As a 

 consequence, the surrounding ligaments become softened 

 and yield, and the articular surfaces displaced. The 

 articular cartilages also suffer, become necrotic in patches, 

 and frequently wholly destroyed. The end result is one of 

 anchylosis of the joint and permanent lameness. 



Prognosis. — With the ordinary dry corn a return to the 

 normal may nearly always be looked for. Similarly, with 

 moist corn, and even with careful treatment of the suppu- 

 rating variety, the same favourable termination may be 

 looked for and promised. 



What cannot so safely be assured is that a relapse will 

 not occur. In other words, the extent of the injury, no 

 matter how serious, does not often offer anything that 

 cannot be overcome by Nature and careful surgery; but 



