AND HIS DISEASES. , 21 



numerous holes. Again, it is not Soft, as in caries : it cannot 

 be punctured -witli the probe, and it is as heavy, if not 

 heavier, than in health. 



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 from the first be 

 given. 



EBTJENATION OE POECELANEOUS DEPOSIT. 



This is, properly speaking, a disease of joints, and should 

 come under. that head. However, as the bone undergoes 

 several very important pathological changes, it may be well 

 to notice it here. It consists of, a polished appearance, pre- 

 sented by the lower end of the thigh-bone and the astragalus 

 or -pulley-shaped bone of the hock, the effects of continued 

 friction. 



Causes. — It generally arises from some injury of the 

 lateral ligaments of the joint, causing an alteration in the 

 motion of the joint. The consequence is, that the friction 

 between the ends of the bones is increased, which produces 

 absorption of the cartilages, and the bones are allowed to 

 rub on one another. The continued friction of the bones, 

 lubricated with synovia, produces the polished appearance. 

 Whatever causes abrasion of the cartilages may give rise 

 to this condition, as concussion, over-stress, &.c. In all these 

 cases, nature throws out an increased secretion of synovia 

 to prevent friction, which causes bulgitjg of the capsular 

 ligament, which is known as bog-spavin. 



Symptoms. — Bog-spavin is always present in these cases, 

 and not unfrequently accompanied by bony deposits around 

 the joint. There is always a certain degree of stiffness or 

 lameness at starting, which goes off as he proceeds. 



