ENLARGEMENT OF THE HOCK— CURB. 267 



more readily diffused among the different bones ; and the joint consisting 

 of six bones, each of them covered with elastic cartilage, and each admitting 

 of a certain degree of motion, this diminished concussion is diff'used among 

 them all, and thereby neutralized and rendered harmless. Each of these 

 bones is covered not only by cartilage, but by a membrane secreting the 

 synovia or oily fluid of which we have spoken in other joints ; so that 

 these bones are formed into so many distinct joints, separated from each 

 other, and therefore guarded from injury, yet united by various ligaments, 

 possessing altogether sufficient motion, yet bound together so strongly as to 

 defy 'dislocation. When, however, we consider the work which this joint 

 has to perform, and the thoughtlessness and cruelty with which that work is 

 often exacted, we shall not wonder if this necessarily complicated mecha- 

 nism is sometimes deranged. The hock is, from its complicated structure 

 and its work, the principal seat of lameness behind. Nine-tenths of the 

 lamenesses that occur in the hind-leg are to be traced to this joint, and 

 when, after careful examination, we are unable to find any other seat of 

 lameness, we shall usually be justified in affirming that the hock is 

 affected. 



ENLARGEMENT OF THE HOCK. 



First, there is inflammation, or sprain of the hock-joint generally, arising 

 principally from sudden violent concussion ; from check at speed ; or from 

 over-weight, and attended with enlargementof the whole joint, and great ten- 

 derness and lameness. This, however, Hke other diff'used inflammations, is 

 not so untractable as intense inflammations of a more circumscribed nature ; 

 and by rest and fomentation, or perchance firing, the limb recovers its action, 

 and the horse becomes fit for ordinary work. The swelling, however, does 

 not always subside. Enlargement, spread over the whole of the hock-joint, 

 remains. A horse with an enlarged hock must always be regarded with 

 suspicion, and is in truth unsound. The parts, altered in structure, are to 

 a certain degree weakened. The horse may discharge his usual work 

 through life, without return of lameness,, but if one of those emergencies 

 should occur when all his energies require to be exerted, the disorganised 

 and weakened part will fail. The purchase, therefore, of a horse with en- 

 larged hock will depend on circumstances. If he has other excellencies, 

 he will not be uniformly rejected ; for he may be ridden or driven mode- 

 rately for many a year without inconvenience, yet one extra hard day's 

 work may lame him for ever. 



CURB. 



There are oftener injuries of particular parts of the hock-joint. We have 

 had occasion frequently to describe the ring-like ligaments, which, in the 

 neighbourhood of joints, so usefully tie down the tendons. From sudden 

 or over exertion these ligaments may be extended, and inflammation, 

 swelling, and lameness may ensue ; or the sheaths of the tendons in the 

 neighbourhood of joints, from their extent of motion in these situations, 

 may be susceptible of injury. Curb is an affection of this kind. It is an 

 enlargement at the back of the hock, about three or four inches below the 

 point of the hock. It is represented at d, p. 262, and it is either a strain 

 in the ring-like ligament which binds the tendons down in their place, or in 

 the sheath of the tendons; oftener, we are inclined to think, of the liga- 

 ment than of the sheath. Any sudden action of the limb of more than 

 usual violence may produce it, and therefore horses are found to * throw 



