196 THE PRACTICE OF VETERINARY MEDICINE. 



cases a surgical operation may be necessary. If the disease 

 is well advanced, however, it is better to have the animal 

 destroyed, especially as it does not injure the quality of the 

 meat for food. The tumour is first of a cartilaginous 

 nature, and it extends, and increases in size until suppura- 

 tion, etc., is established. The parts maybe cut down upon, 

 and all diseased portions of bone removed ; after which, 

 scrape with the bone-spoon, and touch with dilute hydro- 

 chloric acid, or carbolic acid, the latter in the proportion of 

 acid one part, to oil four parts. 



OSTEO-POROSIS. 



This is a non-malignant disease of bone, and of a non- 

 inflammatory type ; it is very commonly known by the 

 name of ' big-head.' It consists of a porous condition 

 of the bones, which are increased in size without propor- 

 tionally^ increasing in weight — in fact, the probability is, 

 that while the bone increases in size it decreases in 

 weight. In most cases of the disease the bones of the 

 extremities are affected, and become enlarged, fragile, 

 ,and often, on very slight exertion, will give way. The 

 disease attacks young animals ranging in age from six 

 months up to four years ; hence it is described as essentially 

 a disease of growth. It is very seldom that the disease is 

 develo^Ded in an animal over four years of age. At Jobs- 

 town, New Jersey, the young horses of Mr. Lorillard 

 suffered severely from this disease. It affects all breeds of 

 horses alike. It is said by some to be due to a deficiency 

 of the salts of lime. I do not think so myself, as frequently 

 horses suffer with the disease in the famous blue grass 

 region of Kentucky, where the grass grows only a few 

 inches above an abundance of lime-stone, and the water is 

 also highly impregnated with lime. It is also said to be 

 due to feeding with maize, or Indian corn, and hay grown 



