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 eacf 

 admitting of a certain degree of motion, this diminished concussion is dif- 

 fused among them all, and thereby neutralized and rendered harmless. 

 Each of these bones is covered not only by cartilage, but by a mombrane 

 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 liga- 

 ments, 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 

 mechanism 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, rising 

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

 over-weight, and attended by enlargement of the whole joint, and great 

 tenderness and lameness. This, however, like other ditlused 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 

 disorganized and weakened part will fail. The purchase, therefore, of a 

 horse with enlarged hock, will depend on circumstances. If he has other 

 excellencies, he will not be uniformly rejected ; for he may be ridden or 

 driven moderately for many a year without inconvenience, yet one extra 

 hard day's work may lame him for ever. 



CUPxB. 



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 the joints, so usefully tie down the tendons. From 

 sudden or over exertion these ligaments may be extended, and inflamma- 

 tion, 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 aflection 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. 'ii)'2, and it is either a strain in 

 ihe rinjr-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 ligament 

 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 out curbs* 



