iU 



DISEASES AND THEIR TREATMENT. 



causes,— scrofula, etc.; but {in the lower animals.it generally arises 

 from local causes, mechanical injuries, extensive destruction of the 

 surrounding soft parts, especially if it involves the artery supplying 

 nourishment to the bone. In young thoroughbred horses, we are 



familiar with it from sore shins, which 

 arises from the animal being put in 

 training too young. The concussion 

 sets up inflammation of the periosteum, 

 which may be followed by caries, but 

 more commonly necrosis of the cannon 

 bone. 



Symptoms.' — The external appearances 

 do not differ very materially from caries. 

 We have sinuses penetrating bone, from 

 which there is a copious discharge of 

 most offensive-smelling matter, in which 

 are occasionally discharged pieces of 

 dead bone which have escaped through 

 the holes in the new bone. This is 

 called the process of exfoliation. It is 

 easily distinguished from caries by the 

 surface of the bone not being worm- 

 eaten, but smooth, and penetrated by 

 numerous holes. Again, it is not soft, 

 as in caries ; it cannot be punctured with 

 the probe, and it is as heavy as in health, 

 if not heavier. 



Treatment. — It must be treated on the 

 same principle as caries. The sinuses 

 must be kept open, frequently washed 

 out, and some stimulant injected, as hydrochloric acid (diluted), 

 and tonics, and good food must be given from the first. 



Exostosis, ,or Bony Enlargement. 



Exostosis is, in general, the consequence of periostitis, or in- 

 flammation of the vascular membrane covering the bone, though it 

 doubtless also arises from other causes. It sometimes comes on 

 without having attracted the least attention, or produced the least 

 apparent disturbance to the animal, and may appear on any bone in 

 the body, or on any part of a bone, sometimes so small as to escape 

 observation altogether, and sometimes very large. It may be 

 caused by external injury, or it may be the result of constitutional 



Fig. 706.— Back Inside View of 

 the Bones of 1 the Hock. 



a, Tibia ; b, Ob calcis ; c, Astraga- 

 lus; d, Cuboides; e, Navicular; f, 

 Outer cuneiform; g, Middle cunei- 

 form; h, Splint; i, Cannon, or shank. 



