DISEASES OP HORSES AND CATTLE. 103 



the animal dies suddenly from over-exertion. 

 Treatment is of no service. 



Hypertrophy of the heart is an increase in its 

 size, the walls becoming very thick. There are 

 three forms of this trouble. First, when the walls 

 are thickened and the cavities retain their capa- 

 city; second, when the cavity becomes enlarged; 

 third, when the walls thicken and diminish the size 

 of the cavity. Leblanc says the origin of this dis- 

 ease depends on a chronic form of inflammation in 

 its walls. 



Symptoms: The impulse of the heart is much 

 stronger than natural, and can be felt lower down ; 

 the sound is louder and metallic. In some cases 

 that I have seen the impulse of the heart could be 

 seen on the right side as well as the left. On look- 

 ing at a horse's sides affected with hypertrophy, 

 you can see the motion, and sometimes it can be 

 heard at a little distance. There is no cure for it, 

 and the animal may do slow, light work for a few 

 years. 



Rupture of the heart sometimes occurs in the 

 horse from over-exertion arid shocks; such as strik- 

 ing against some solid body, the result of falls. 

 Sometimes a horse may drop on the race-course 

 from rupture of the heart. Sudden fright will cause 

 it. I remember one case of rupture in a young 

 mare from being forced up to a locomotive. The 

 animal began to tremble violently and dropped 

 dead in a few minutes. A post-mortem revealed 

 rupture of the left ventricle of the heart. I men- 

 tion this, as I do not think it wise to force a horse 



