DISEASES AND TREATMENT OF THE HORSE. 191 



troubled again. Watch that his kidneys are in good shape, and 

 have the animal exercised every day. If you have fear of a horse 

 becoming attacked with this disease when you are going to drive 

 him let him walk easy for the first mile or bo, and then he will b« 

 all right 



CHAPTER XX. 



DISEASES OF THE BONES. 



BIG HEAD (OSTBO-POROSIS). 



This disease is more common in some localities than others ; 

 it is not met with much in Canada or Great Britain, but is frr 

 quently seen in the United States and Mexico. It is a disease 

 which attacks horses from one to four years old, and rarely 

 attacks old horses, and it gradually comes on as the animal 

 grows, without any signs of soreness, only the bones of the head 

 and legs get larger and lighter and become very brittle, that is, 

 easy to break. Thus it gets the name "big." It more often affecti 

 the bones of the head than tho^e of any other part of the body. 



Causes. — It is difficuU *t- cay what is the real cause of thl« 

 disease, but it is suppos>"»'^ f» b« caused from an animal feeding on 

 pasture land deficient io the salts of lime. Some think it is 

 wholly c»'Ss'^'i from animals grazing on low-lying, swampy land, 

 where the ^rass grows long and does not contain the full amount 

 of nouri.<h«ng substances. 



Symptoms. — At first the symptoms are not very well marked, 

 but the animal is noticed to be dull, fall off in condition, and his 

 muscles get very soft. The aninml may run along this way for 

 four to six months, then the true nature of the disease will show 

 itself. The animal will seem stiff in traveling, his belly becomes 

 very gaunt, and the bones of the head will be noticed to be getting 

 larger than natural; then, after this, the bones of the legs may 

 also become enlarged, and as the disease goes on the bones will 

 continue getting larger, and the animal keeps gradually going 

 down in condition until he dies. In some cases the bones become 

 so brittle that while he his walking along one of hi* legs would 

 break and he would have to be destroyed. 



Treatltient. — The treatment is not very successful, and if the 

 disease has been running on for any length of time it is best to 

 destroy the animal. If in the early stages, and he U <i»a low 



