DISEASES OF THE FOOT AND SHOEING 197 



with the serviceabiUty of draft horses after lameness ceases. 

 Unlike spavin and some other kinds of lameness, horses do not 

 "warm out" of sidebone lameness. 



TOE AND QUARTER CRACKS 



Sand crack is another term for these diseases. They are splits in 

 the horn of the wall, the position determining the exact name applic- 

 able. The causes are lack of moisture in the hoofs; heavy shoes; 

 nailing the shoe too close to the quarters; separation of the horn 

 from the pododerm. The crack first appears at the coronary band, 

 from where it gradually extends downward either by growth or by 

 splitting the horn. Lameness is caused if the fissure is deep. The 

 first step in treatment consists in removing the shoe and softening 

 the horn by poultices, or by standing in water for a few days. If 

 the sensitive tissues at the coronet can be made to secrete horn of a 

 resistant nature, the crack will disappear in time at the lower border 

 of the wall. To aid in this, a piece of the bearing surface in contact 

 with the shoe about 2 inches long should be cut away to prevent 

 pressure. Shoeing with a bar-shoe is helpful. The edges of the 

 crack may be drawn together with a nail. It takes about one year 

 for a sand crack to grow down. The disease is an unsoundness. 



CANKER 



Canker results from infection of the pododerm or foot-skin. 

 It is a disease with, a slow course, during which a gradual under- 

 mining of the horn of the sole and frog takes place. Unless relief 

 is given these structures eventually loosen. Treatment is purely 

 local, and consists in providing dry quarters, removal of all in- 

 volved tissues, applying antiseptics, and in protecting the exposed 

 sensitive parts from external influences. Most cases of canker 

 require several weeks and often months of careful treatment for a 

 cure. 



CONTRACTED HEELS 



Contracted heels is a narrowing or "tied-in" condition most often 

 seen in the front feet. Lack of exercise, too little moisture, thrush, 

 or navicular disease may produce contraction. It is, therefore, a 

 symptom of some other affection rather than a disease itself. 

 Remedial measures are given in connection with these other 

 diseases. 



