876 RING-BONE. 



Diagnosis is seldom difficult, the condition of the sesamoids and 

 the character of the lameness being often sufficient to form an opinion, 

 provided no other disease of the limb exists. Exostoses sometimes 

 occur on the sesamoid bones, particularly on their lateral surfaces, 

 without causing a trace of lameness, and, from their symmetrical 

 appearance in both limbs, often give the impression of being 

 congenital. Before delivering a prognosis, it is advisable thoroughly 

 to examine the flexor tendons, and to make sure whether the fetlock- 

 joint can be fully flexed. 



Treatment. During the stage of acute inflammation, and 

 particularly when the flexor tendons exhibit recent swelling, the 

 animal should be rested, and the fetlock-joint, as far as possible, 

 fixed by a firmly applied bandage, moistened with warm water, 

 or, in case of great pain, with a continual current of cold water. 

 Good results sometimes follow firing and blistering, though six to 

 eight weeks' rest is then necessary. Old-standing cases are not 

 often benefited by such treatment. Neurectomy is the only means 

 of permanently removing lameness ; and, considering the seat of 

 disease, it is better to divide the median than the plantar nerve. 



V.- RING BONE. 



The term tk ring-bone " has been used since olden time to indicate 

 many chronic diseases about the coronary joint attended with 

 enlargement. At first such enlargements were regarded as resulting 

 from a single cause, but careful anatomical examination shows that 

 they may be due to very different disease processes. The following 

 forms of ring-bone have been differentiated : — 



(1) Articular ring-bone. This consists in an arthritis chronica. 

 Sometimes it consists of an arthritis chronica deformans in which the 

 articular cartilage forms the point of origin of the disease, sometimes 

 it follows synovitis. The articular cartilage of the os suffraginis or 

 os coronae is found to be more or less altered, according to the age 

 of the disease, whilst exostoses occur on the borders of the joint 

 (Fig. 497). We, therefore, have to deal with an arthritis sicca vel 

 deformans. In the later stages the suffraginis and coronet bones 

 become covered with extensive ossific deposits, whilst the articular 

 cartilage is totally destroyed ; obliteration of the joint (synarthrosis) 

 may even occur, as shown by numerous reported cases. 



(2) Periarticular ring-bone. In consequence of chronic 

 periarthritis produced by displacement, or by continued strains 

 on the limiting apparatus of the joint, thickening occurs, particularly 



