392 



Treatmeni. — Thrushes are to be treated by cleanliness, the removal 

 of all exciting causes, and a return of the frog to its normal condition. 

 As a rule, the diseased and ragged portions of horn are to be pared 

 awaj^, and the foot poulticed for a day or two with boiled turnips, to 

 which maj' be added a few drops of carbolic acid or a handful of pow- 

 dered charcoal to destroy the offensive smell. The cleft of the frog 

 and the grooves on the edges are then to be cleaned and well filled with 

 dry calomel, and the foot dressed with oakum and a roller bandage. 

 If the discharge is profuse the dressing should be changed daily, 

 otherwise it may be left on for two or three days at a time. Where 

 a constitutional taint is supi^osed to exist Avith swelling of the legs, 

 grease, etc., a purgative followed by dram doses of sulphate of iron, 

 repeated daily, may be prescribed. In cases where the growth of horn 

 seems too slow, a Spanish fly blister applied to the heels is often fol- 

 lowed by good results. Feet in which the disease is readily induced 

 may be protected in the stable with a leather boot. If the thrush is 

 but a sequel to other diseases a permanent cure may not be possible. 



CANKER. 



Canker of the foot is a disease due to the ra^iid reproduction of a 

 vegetable parasite. It not only destroys the sole and frog, but by set- 

 ting up a chronic inflammation in the deeper tissues, prevents the 

 growth of a healthy horn by which the injury might be repaired. 

 Heavy cart horses are more often affected than those of any other class. 



Causes. — The essential element in the production of cankers is of 

 course the presence of the parasite; consequently the disease may be 

 called contagious. But, as in all other diseases due to specific causes, 

 the seeds of the disorder must find a suitable soil in which to grow 

 before they are reijroduced. It may be said, then, that the conditions 

 which favor the i)reparation of the tissues for a reception of the seeds 

 of this disease are simply predisposing causes. 



The condition most favorable to the development of cankers is 

 dampness — in fact, dampness seems indispensable to the existence 

 and growth of the parasite ; for the disease is rarely, if ever, seen in 

 high, dry districts, and is much more common in vsauy than in dry 

 seasons. Filthy sta])les and muddy roads have been classed among 

 the causes of canker; but it is very doubtful if these conditions can 

 do more than favor a preparation of the foot for the reception of the 

 disease germ. 



All injuries to the feet may, by exposing the soft tissues, render the 

 animal susceptible to infection; but neither the injury nor the irrita- 

 tion and inflammation of the tissues which follow, are sufficient to 

 induce the disease. 



For some unknown reason horses with lymphatic temperaments, 

 thick skins, flat feet, fleshy frogs, heavy hair, and particularly with 

 white feet and legs, are especially liable to canker. 



