246 THE HORSE 



narrow hoofs, which have a natural tendency to contract, and 

 are frequently referred to as donkey or mule's feet. These 

 are very apt to have ill-developed frogs, while those with 

 open and broad but possibly thin soles, have the frogs very 

 well developed indeed. 



The outer frog is an elastic wedge-shaped pad, whose 

 chief function is to minimise concussion and jar, when 

 the whole weight of the horse is thrown violently upon 

 the foot, and it also acts as a drag in preventing slipping, 

 more especially when travelling on rocky or slippery 

 ground. It likewise is reduced naturally by exfoliation, and 

 therefore should not be cut away with the knife ; but since 

 it is apt to become ragged and torn in the course of work, 

 these frayed portions should be trimmed off by the smith, for 

 they otherwise form receptacles for dirt, which is certain to 

 absorb moisture from the soiled litter in the stable, when 

 these pockets become originators of disease. The decaying 

 tissue of the frog has an offensive odour peculiar to itself, 

 and on this being perceived close investigation should im- 

 mediately follow, and the affected part be at once removed. 



One other caution must be given. On no account should 

 the smith rasp away the outer portion of the crust, for by so 

 doing he not only reduces the thickness of the sustaining 

 wall, which is narrow enough to begin with, but he also 

 removes the glazed waterproof surface, which has a valuable 

 service to perform in preventing the escape of the inner 

 moisture of the foot, and without which the horn becomes 

 so dry as to encourage sand-crack and other evils. It is 

 necessary, however, for the smith to use the rasp to file off 

 the ends of the nails after they have been clinched, and 

 to smooth down the projecting portions level with the crust, 

 but if this is carefully done there need be no weakening 

 of the wall itself. 



How long a time shoes should last depends much upon 

 the ground on which the work is done, for it is plain that a 

 horse travelling entirely on the road will wear his shoes out 

 quicker than one who is scarcely ever out of the field. The 

 character of the ground also has much to say to it, for if it is 

 hilly the shoes are more quickly worn at the toes than 



