166 



DISEASES OF THE FEET. 



balled in the feet, thereby causing the frog and sole to become 

 heated hj stopping evaporation of moisture from them. The 

 ill effects of the tan, in this case, can be entirely obviated by 

 frequently picking out the feet, so as to prevent the tan becoming 

 caked in them. The same remarks apply, more or less accurately, 

 to the use of moss litter and sawdust. 



Thrush is more frequently found in the hind than in the fore 

 feet; (1) because, in badly-managed stables, the dung and urine 

 of horses are often allowed to accumulate under the hind feet 

 for a considerable time ; and (2) because the hind feet being natu- 

 rally more upright and concave than the fore feet, their frogs are 

 less exposed to pressure. 



In England, thrush much more commonly affects the off feet 

 than the near ones, on account of the idiotic custom, among English 

 grooms, of attending to the feet only from the near side. 



Thrush is, I think, never induced solely by constitutional causes. 

 To prove such a case, it would be necessary to show that the affected 

 foot had been kept dry, in the stable, and that the frog had been 

 subjected to pressure for a considerable time before the attack. 

 Under these conditions I have never known of an instance of thrush. 



In the tropics, maggots are sometimes found within the cleft of 

 a frog which suffers from thrush. Their presence, as might be 

 expected, greatly aggravates the disease. 



In neglected cases, the horny covering of the frog may rot off, 

 and the red and bleeding sensitive parts become exposed. 



TREATMENT. — If there be no lameness, keep the feet dry, and 

 avoid " stoppings." Carefully remove with the drawing knife or 

 searcher (Fig. 50) any diseased or loose portions of horn, in order 

 to prevent dirt or wet accumulating about them. The " drawing 

 knife " is the peculiarly-shaped knife with which a blacksmith 

 pares a horse's foot ; and a " searcher " is a fine and narrow-bladed 

 drawing knife. Into all the parts from which either discharge or 

 bad smell issues, introduce one of the following applications : — 



(1) Burnt alum 



(2) Calomel 



(3) Formalin ... ... ... ... ... 1 part. 



