196 DISEASES OF THE HORSE’S FOOT 
get pressure upon and final gangrene of the sensitive sole 
and of the sensitive lamine 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 lamine of the 
wall, in which case, if a dependent orifice is quickly made 
at the sole, the injury to the lamine 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 
oceurs 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. Asa 
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 
