General Diseases of Bones, Joints and Muscles. 295 



droops, and the hind limbs are brought unnaturally for 

 ward beneath the belly. 



Lameness in both hind limbs is marked by the back- 

 ward position of the fore feet, the short rest and weak 

 impulse of the hind on the ground, the extension and 

 drooping of the head, and above all the difficulty of back- 

 ing- 



Lameness in the two Umbs on the same side determines 

 a gait approaching the amhJe or rack, with the firm plant- 

 ing of the opposite members. Lameness of one fore and 

 the opposite hind produces a simple exaggeration of the 

 gait caused by disease in one of these hmbs. When J;he 

 cause of lameness exists in more than one limb it is diffi- 

 cult to make the ani)nal keep the trot. 



La aU cases it is well to have the animal driven or 

 ridden so as to heat him, and then keep him perfectly 

 stiU for half an hour to cool, before completing the exam- 

 ination, as many lamenesses will disappear when the 

 subject is warmed by exercise. 



DISEASES OF BONES. 



These may be divided into : — inflammation of the bone 

 itself (ostitis), or of its fibrous covering (periostitis), which 

 may result in softening, consolidation or induration, enlarge- 

 ment, bony groiutlis and tumors, abscess, ulceration and death 

 (necrosis). Beside these there are the degenerations and 

 diseases of bone such as deficiency or excess of earthy salts, 

 with binding or brittleness of the bones ; tubercle, cancer, 

 and sarcomatous, cartilaginous, cystic, vascular or other tu- 

 mors, etc. 



But the great mass of bone diseases in the domestic 

 animals consist in inflammation and its results, to which, 

 accordingly, the following remarks will be mainly con- 

 fined. Every bone is permeated even in its densest parts 

 by an abundant network of minute blood-vessels, and 

 studded throughout with microscopic soft elements (nu- 

 cleil which approiDriate the suitable materials from the 



