324 THE PRACTICE OF VETERINARY MEDICINE. 



on the American continent at least, exercised on hard tracks. 

 Shoeing with high-heeled and high-toed shoes has a ten- 

 dency to produce sand-crack, and certain influences, as 

 irregular exercise, high feeding, etc., by interfering with or 

 impairing the normal secretion of the horn, may predispose 

 to the condition. Hot and dry weather, standing on a very 

 hard and dr^' floor, and dryness to an unnatural degree of the 

 horn from any cause whatever, undoubtedly exert a certain 

 amount of influence in the production of sand-crack. There 

 is nothing better for a horse's feet than to be out on a wet 

 day, the dampness keeping the horn j^liable, moist, and 

 tough, hence acting very efficaciously as a preventive of 

 sand-crack. 



Symptoms. — The crack usually appears very suddenly. 

 The animal shows more or less lameness, and on an ex- 

 amination being made, a slight crack is discovered just be- 

 tween the hair and the hoof, and there may be a slight 

 oozing of blood. The solution of continuity is of course 

 the special characteristic of the condition. It may exist 

 for a day or two without producing lameness, and in some 

 cases the presence of the crack is the only symptom. 

 Generally there is more or less lameness in connection with 

 it, from the fact that when the foot is placed upon the 

 ground the crack spreads, and on removing the foot from 

 the ground the crack closes, and, pinching the sensitive 

 structures, gives rise to pain and lameness. The crack 

 usually commences above, and extends downwards. Some- 

 times the crack may be concealed by the hair around the 

 coronet, and a frequent practice of dishonest persons before 

 offering such a horse for sale is to conceal the existence of 

 the crack by filling it with various substances, as gutta- 

 percha, shoemakers' wax, tar, hoof ointment, etc. ; and if 

 properly done, the existence of the crack can scarcely be 

 discovered, defying any but the closest scrutiny. Some- 



