EING-BONE. 247 



on laxative food. If the animal be a young race-horse, he will 

 probably be fit to resume easy work in about ten days. 



In neglected cases, or if the blister does not succeed in 

 producing the desired effect, and the swelling is very extensive 

 and the pain great, periosteotomy (p. 241) must be performed 

 without loss of time, in order to admit of the escape of the 

 exudation, which, by the pressure it exerts on the inelastic and 

 highly sensitive periosteum, is the cause of the intense pain and 

 fever. Besides, if the exudation be considerable, and allowed to 

 remain between the surface of the bone and the periosteum, death 

 of the bone may ensue; the process being, that this exudation 

 becoming converted into bone will block up the small canals 

 through which the bone receives nourishment by means of small 

 blood-vessels proceeding from the periosteum. Before operating, 

 carefully feel for the position of the extensor tendons (Fig. 7, p. 

 33) which run down the front of the cannon bone, so that these 

 important structures be not injured. 



If pus forms under the periosteum, periosteotibmy should be 

 performed without loss of time; for the pus will corrode the 

 tissues, and may give rise to blood-poisoning. 



After a severe case of sore shins, an appropriate rest should be 

 allowed. When the horse is put to work again, he should be 

 exercised only on soft ground, so that there may be a minimum 

 of the original cause of the disease, namely, concussion. At first 

 the work should be confined to walking, trotting, and slov/ 

 cantering; time is the great healer of this disease. When the 

 horse is galloped, the distance should be short, and the work, if 

 need be, repeated, with about half an hour's walking exercise 

 allowed between the " spins,'' so that the bones of the legs may 

 be saved from long-continued jar. The advisabilty of warm 

 fomentations after a gallop will naturally suggest itself to the 

 trainer. 



An attack of sore shins, in which the exudation has been 

 excessive, will give a more or less rounded appearance to the 

 front part of the cannon bone when viewed in profile. 



Ringbone (Fig. 87). 



This vague term is applied to bony deposits on the pastern bones, 

 and is, for convenience' sake, divided into three kinds, namely : — 

 (1) False ringbone, which may be regarded as a bony deposit on 

 the long pastern bone, situated on one or both sides of it : in some 

 cases it extends to the front of the bone. This form, although not 

 nearly such a serious affection as the next two kinds, occasionally 

 causes lameness on account of its presence interfering with the 



