DISEASES OF BONES 



215 



stables, and Professor Varnell saw reason to regard it in one instance 

 as in some way connected with a too exclusive bran diet, and deficiency of 

 lime in the food. It is quite clear that the precise nature and conditions 

 of the origin of the disease still remain to be determined. 



Symptoms. — The first noticeable indications of the affection are slight 

 stiffness and subsequent lameness in one or more of the limbs, with tender- 

 ness over the region of the joints, which sooner or later become enlarged. 



The disease may attack all the limbs 

 more or less severely at once, or in 



Fig. 321. — O.steo-porosis 



Bones of the face enlarged, thickened, and 

 rendered soft and sponcfv. 



Fig. 322. — Osteo-porosis 

 Lower Jaw affected by the disease. 



succession at varying intervals of one to three weeks. At the .same time 

 the head and face attract attention by the gradual obliteration of their 

 sharp angles, and the steady increase in size of the head as a whole. At 

 this time there is no perceptible constitutional disturbance. The animals 

 feed and rest and keep their condition. The swelling of the joints may 

 to some extent subside, only, however, to return again and add to the 

 permanent enlargement. 



As the di.sease progresses the bones continue to increase in size and 



