DISEASES OP BONES 193 



Describe the changes in an osteomaliUc hone. 



The pelvic bones and those of the limhs are of special 

 interest. In the beginning, there is simply hyperemia of 

 ■the affected bone, small hemorrhagic foci being noticeable on 

 section of the bone. As the disease progresses the hyperemia 

 ^tate becomes marked, the bone on section exhibiting bloody 

 extravasation in the marrow and red punctation on the bone. 

 "When the disease advances yet more the bone becomes soft. 

 The bone cells are replaced by fat cells. In short, the bone 

 tissue degenerates until it becomes medullary tissue; the latter, 

 increasing in bulk, becomes fatty, taking the place of bone 

 "tissue proper. 



OuUine the symptoms of osteom,alacia in the living animal. 



Perverted appetite, general depraved appearance. The 

 ■creatures lie down a great deal, they are hide bound, the ani- 

 mals walk stiffly. In well advanced cases, fractures, distor- 

 tions of the bones of the pelvis and legs are common. 



Sow do you treat osteomalacia ? 



Change the diet to one rich in lime, give phosphorus with 

 •oil in doses of from 3 to 3 grains for cattle. In man the 

 removal of the ovaries and testicles has given splendid results 

 in the treatment of osteomalacia. 



Osteoporosis of tlie Horse. 



What is osteoporosis ? 



It is a rarefying osteitis, a form of osteomalacia peculiar 

 to the young and adult horse. 



What are the causes f 



They are obscure. A great many facts point toward a 

 microbian origin, the pathogenic bacterium either acting as 



