DISEASES. 649 



A vicious adjustment also contributes to contraction. When the 

 shoe is so prepared that its upper face is concave, and its branches 

 form a plane inclined from without inward, and when this face 

 extends back to the heels, there is a circular pressure produced 

 upon the inferior border of the wall. This is a case in which the 

 foot has a tendency to droj), pressed in as it also is by the weight 

 of the body as the foot rests on the ground. 



Another wrong practice is to place the nails too near the heels. 

 The fixing of the shoe on the foot tends always to jDroduce con- 

 traction, as Bracy Clark observed ; it especially prevents the wide- 

 ening of the hoof, as remarked by Eodet and Coleman. But this 

 effect of the nails is well marked at the heels, where they prevent 

 the dilatation of that part of the foot. 



These effects of shoeing are to be observed so much the more 

 rapidly and seriously when the hoof is thicker, denser, and of a 

 finer structure, as it is observed in small feet. In these feet, the 

 hoof grows more rapidly, and is on this account more ready to 

 contract. Let us now consider that this effect of shoeing is jjer- 

 manent, and that to the effect of a first shoeing comes to be added 

 that of a second, of a third, and so on, and we can readily under- 

 stand how truly the great number of contracted heels one may 

 meet with can be attributed to erroneous shoeing. 



Inaction is also an important cause, as, sa^'s Turner, the horse 

 is by natui-e destined to be always in motion ; it is a condition of 

 its health, and it is on account of this condition that in the state 

 of nature he is free from contracted heels. It is, on the contrary, 

 because the domesticated horse is confined within a stall for hours 

 and days, that his feet become contracted. We have seen colts 

 raised without exercise, whose feet were contracted before they 

 were shod. 



Contraction of the heels is often the result of other diseases of 

 the hoof, and of other lameness. It is commonly associated with 

 corns, navicular disease, punctured wounds of the plantar region, 

 accompanied with long sensitiveness of the posterior parts of the 

 foot, after-diseases of the frog, thrushes, side bones, phalangeal 

 articular diseases; in fact, after all affections of long standing, 

 even if they have their seat in the upper segment of the frog. 



Finally, heredity has been named as one of the causes. This 

 cannot be denied as to some breeds, principally of meridional 

 climates, as a consequence of the organization of their feet, which 



