DISEASES OP HORSES AND CATTLE. 223 



notice a few years ago. A five-year-old stallion 

 was tracked for a month with the intention of 

 putting him into the fall races. After being driven 

 one or two heats, all at once he would go lame in 

 one hind leg, so lame at times he could not be 

 moved off the track. After resting for ten or fifteen 

 minutes he could walk fairly well, and in half an 

 hour's time would be as well as ever, and might 

 trot several times around the track all right ; but if 

 put to his speed after trotting for a while the same 

 thing would take place. I was requested to ex- 

 amine the horse. I found him at rest and could 

 not discover anything wrong, so I had him speeded. 

 He went twice around all right, but after passing 

 the first quarter pole he went on three legs. I was 

 at his side as quickly as possible, and found the 

 large muscles of the back of the thigh badly 

 cramped and as hard as iron. In a few minutes 

 they began to relax and the animal was able to 

 walk to his stable. I considered this was caused 

 by the nerve supplying these muscles being de- 

 ranged in some way by the driving, as it required 

 violent exercise to develop it. I ordered the animal 

 to be rested for a couple of months and to have one 

 dram of powdered nux vomica and one dram sul- 

 phate of iron once daily in a small bran mash. 

 The animal was then put on the track again and 

 did good work for three weeks, when the old 

 trouble showed itself again. The animal was then 

 taken off the track for the winter, during which he 

 did some moderate driving. In the following sea- 

 son he was put on the track, and as long as I knew 



