^^v 



\ 



I 



CHAPTER XVI. 



JABTICULAR LAMENESSES — continued, 



DISEASES OF THE HOOK BOQ-SPAVIN — BONE-SPAVIN CONFORMATION 



OF HOCK MOST SUBJECT TO SPAVIN — THOROUQH-PIN— CAPPED 

 HOCK — INJURIES TO GASTROCNEMH MUSCLES— CURB. 



DISEASES OF THE HOCK. 



The tarsus or hock corresponds to the ankle-joint of man. Its 

 diseases" may be divided into three classes, namely — (1.) Dis- 

 eases of the true hock-joint (that composed of the tibia and 

 astragalus) ; (2.) Diseases of the gliding articulations formed by 

 the cuneiform bones ; and (3.) Diseases of its ligamentous and 

 tendinous structures. 



L DISEASES OF THE TRUE HOCK-JOINT. 



Bog-Spavin. — A bog-spavin, when caused by inflammation of 

 the joint, is a tense, fluctuating swelling, accompanied by heat 

 and pain. In such instances it is an unsoundness indicating a 

 change within the textures of the joint. There are bog-spavins, 

 however, which may not be looked upon as constituting unsound- 

 ness, being m^re dropsy of the articulation, arising from some 

 fault of conformation. Professor Dick maintained that such 

 collections were " mere stores of synovia for lubricating the joint, 

 thus proving the best preventatives of disease, by preventing 

 friction." These kinds of bog-spavins are most frequently found 

 in very upright or in very crooked hocks, and in weak hocks of 

 any description ; because in all these forms concussion is most 

 severely felt, and exertion is likely to be injurious. In all 

 probability the hyper-secretion of synovia is due to some 



