1014 DISEASES OF THE HOCK. 



or forms a complication of that disease, in consequence of the chronic 

 arthritis extending to the outer surface of the joint. 



It not infrequently happens that the head of the outer small 

 metatarsal bone is abnormally prominent, or is rendered so by the 

 development of an enlargement. It then forms a projection beyond 

 t he general vertical line of the hock, best seen when the joint is viewed 

 from behind. This is the condition known in France as " jarde." 

 Gillet, Sipierre, Goubaux and Barrier, all of whom studied the 

 condition, state that it does not affect the hock-joint, but is invariably 

 confined to the head of the small metatarsal and the ligament con- 

 necting the latter with the large metarsal. Other authors, however, 

 believe that it may extend to the hock -joint and produce on the outer 

 surface a condition similar to spavin. 



Hertwig insisted that horses often go lame from this condition, 

 and show jerking movements of the limb similar to those seen in 

 spavin. Moller has only seen lameness where the enlargement was 

 accompanied by spavin. As a rule, when lameness is present there 

 is acute inflammation of the outer lateral ligament or of the 

 periosteum. 



Diagnosis. The examination for this enlargement is similar to 

 that for spavin. The outer Surfaces of the hocks should be compared. 

 As a rule, it is easy to discover whether the skin alone is thickened, 

 or whether the deeper-lying structures are involved. 



The prognosis is usually favourable. Only when spavin is also 

 present is the prognosis doubtful. 



Treatment is usually unnecessary. If the ligaments and 

 periosteum are acutely inflamed, they should be treated accordingly. 

 In most cases rest and blistering remove the lameness, though 

 thickening seldom disappears, and a slight blemish may always 



VII. -CURB. 



With horsemen, the name curb is applied to all swellings on the 

 posterior surface of the hock-joint. Seen from one side, the back 

 of the hock-joint should appear as an absolutely straight line, stretching 

 from the tuber calcanei to the fetlock. About 3 — 4 inches below 

 the point of the calcis a swelling or convexity sometimes appears. 

 (The French " courbe " is not identical with the English " curb." 

 It represents a bony enlargement on the inner surface of the lower 

 extremity of the tibia.) 



In or about the posterior region of the hock, in certain cases, 

 enlargements occur and are due to abnormal devolpment of the head 



