DISEASES OF THE BONES. 



173 



known as osteo porosis. This disease is essentially a disease of 

 growth, and in this particular it resembles rickets. It is seldom 

 seen in horses over twelve years of age. 



Causes. — The causes producing this disease have been a mys- 

 tery. It prevails most extensively in low-lying lands and in 

 damp places. All classes of horses, mules, ponies, sheep, and 

 cattle, no matter how fed and treated, get the disease in certain 

 localities and under certain conditions. I have been unable, 



Fig. ?A — Osteo Porosis. 

 Side view. The dotted lines show the enlargement. 



after thorough investigation, to trace the cause of the disease to 

 feed. The water and feed may be predisposing causes, but they 

 will not jjroduce the disease in themselves. The symptoms are 

 more aggravated during the winter months, and the disease is 

 more prevalent where stables are located on low, marshy land. 



For the last five years the disease has prevailed to a consid- 

 erable extent at Lambert's Point, Virginia. This point of land 

 lies on the Elizabeth River, only a few miles from Hampton 

 "Roads- "With but few exceptions the farms on this point have 



