CAUSES OF CONTRACTED FOOT. 345 



hoofs were flat, in the other upright. The horse with flat hoofs 

 suffered from contraction, the other did not, the reason appear- 

 ing to be simply that in upright hoofs the heels bear less 

 weight than in flat hoofs. 



As a rule, when the formation of the limb as viewed from in 

 front appears normal, both heels contract equally, but when the 

 toes are turned in or out contraction is unequal. AVith turned- 

 out toes the inner, with turned-in toes the outer, heel appears 

 to suffer most. Once the heel contracts sufficiently to run 

 downwards and iniuards, the body-weight aggravates the condi- 

 tion. The heel becomes more and more oblique and the 

 affected half of the frog diminishes in size. The os pedis wing 

 of the same side also suffers and may undergo atrophy. The 

 change progresses with a rapidity proportioned to the extent to 

 which the toes are turned out or in, and is sometimes very 

 marked in flat feet. When contraction is limited to one side 

 of the foot the bulbs of the heel may be displaced. 



(h) Exciting Causes. — 1. The first of these is defective shoe- 

 ing, that is, not only the use of badly constructed shoes but 

 faulty preparation of the feet. 



Of the latter class of errors perhaps the most serious is 

 weakening the bars and frog by excessive paring, and next, 

 thinning the sole. It may be laid down as a principle that to 

 remove more than loose horn is a fault. Fortunately, excessive 

 use of the knife is much less common than formerly ; at one 

 time it was usual to pare the parts until the sole yielded to the 

 pressure of the finger and spots of blood appeared on the frog. 

 In-curved heels, which tend to compress the frog, should be 

 carefully lowered without weakening the union between heel, 

 frog, and bar (see fig. 331, a, h). "When the heels are lowered 

 overmuch the toe becomes disproportionately long and the axis 

 of the foot distorted, so that worse e'ffects are produced than 

 by corresponding lowering of the toe. The direction of the 

 foot axis must always be kept in view when paring the foot. 



In flat hoofs contraction may also be favoured by insufficient 

 paring or by allowing the shoes to remain on for too long a 

 time. 



Shoes with bearing surfaces inclined inwards at the heels 

 and shoes fitted too wide, that is, in which the heels (of 

 the shoe) do not cover those of the hoof, compress the latter. 



