THE FOOT 687 



the previous pages. If the foot-pad be cut away in shoeing and no 

 pressure given it, contraction occurs as a result, in consequence of 

 loss of function of the food-pad and plantar cushion. Inflamma- 

 tion of the glands of the plantar cushion leads to an offensive dis- 

 charge known as Thrush, which erodes what is left of the horn of the 

 foot-pad. This condition is aggravated by dirt, and is therefore 

 common in the hind-feet, but its chief cause is a want of proper 

 foot-pad pressure. The horn of the sole and foot-pad, from causes 

 which are not clearly known, but probably microbic, takes on an 

 unhealthy, cheese-like, and offensive condition, due to disease of the 

 horn-secreting membrane of these parts. It is a most intractable 

 disease, known as Canker, and is frequently associated with defec- 

 tive hygienic care. The layer of white horn at the toe between the 

 insensitive laminae and the outside wall is liable to a curious dis- 

 integration known as Seedy Toe, which, by extension, may excavate 

 the wall nearly as high as the coronet. It is a slow process, and 

 recovery is tedious. The hoof frequently shares in any general 

 disturbance of the system. There is a tropical form of skin disease 

 in which the hoofs frequently indicate by the scaly condition of the 

 wall that the horn-secreting substance — a modified skin — is sharing 

 in the general disorder. Similarly, the growth of the feet may 

 from constitutional causes be temporarily inhibited, and then start 

 again with renewed vigour ; every increase in the production of the 

 wall being marked by a ring which extends all round the hoof. From 

 the same cause, horses exposed to standing in wet places like marshes 

 have an impetus given to the growth of the wall, resulting in rings 

 on the feet. 



The above indicates the numerous diseases or injuries to which 

 the foot is liable. The foot has a special pathology, as well as a 

 special physiology. It is the most common seat of incurable lame- 

 ness, and has always been so since the horse was domesticated. 

 ' No foot, no horse,' is as old as the days of Xenophon. This horse- 

 master tells us how to keep the horn of the feet of cavalry horses 

 hard — a very necessary matter at a time when shoes were unknown. 

 It is a remarkable fact that the horn of unshod feet is infinitely harder 

 than that of horses wearing shoes. It may, indeed, be so hard as 

 to resist the entry of a nail. 



