290 THE HIND LEGS. 



it can be found, and there is no external h^at or enlargement to indicate its seat. 

 Farriers and gTooms pronounce these to be affections of the stifle, or round bone ; or, 

 ,f the gait of the horse and peculiar stiffness of motion point out the hock as the 

 affected part, yet the joint may be of its natural size, and neither heat nor tenderness 

 can be discovered. The groom has his own method of unravelling the mysterj'. He 

 says that it is the beginning of spavin; but months and years pass aAvay, and the 

 snavin does not appear, and the horse is at length destroyed as incurably lame. 

 " Horsemen are indebted to Mr. W. J. Goodwin, V. S. to Her Majesty, for the dis- 

 covery of the seat of frequent lameness behind. The cut, p. 286, represents the two 

 layers of small bones within the hock — the larger wedge-like bone e, above ; and the 

 middle /, and the smaller one below, and it will be seen that almost the whole of the 

 weight of the horse, communicated by the tibia a, is thrown upon these bones. The 

 cube-bone d does little more than support the point of the hock c. It is then easy to 

 imagine that, in the concussion of hard work or rapid travelling, these bones, or the 

 delicate and sensible membranes in which they are wrapped, may be severely injured. 

 Repeated dissections of horses that have been incurably lame behind, without any- 

 thing external, during life, to point out the place or cause of lameness, have shown 

 that inflammation of the membranes lining these joints, and secreting the fluid that 

 lubricates them, has taken place. 



Mr. Goodwin narrates a very interesting case in corroboration of this account of 

 hock lameness. The author of this work had the honour of being present when the 

 examination took place. " The patient was a harness horse of unusual perfection, 

 both in shape and action, and was a great favourite with an illustrious personage. 

 He suddenly became lame behind on the off-leg, but without the least accident or 

 alteration of structure to account for it. He was turned out for a short time, and the 

 lameness disappeared. He was then incautiously made to perform his usual work, 

 until perfectly incapacitated for it by returning and aggravated lameness. Suspect- 

 ing the seat of lameness to be in the hock, although the joint was perfectly unaltered 

 in form, he was, three m^onths cJter the commencement of the lameness, blistered and 

 fired, and placed either in a loose place or paddock, as circumstances seemed to re- 

 quire. Not the least amendment took place at the end of six months, even in his 

 quiescent state, and, after twelve months from the time of his being given up for 

 treatment, he was destroyed, his case being naturally considered a hopeless one. 

 Ulceration of the synovial membrane was found, taking its origin between the two 

 cuneiform bones. These bones had become carious, and the disease had gradually 

 extended itself to other parts of the joint. Mr. Goodwin had no doubt that if the 

 animal had been suffered to work on for any greater length of time, necrosis, or an- 

 chylosis of every bone concerned in the hock, would have been the result."* — {Vete- 

 rinaria'n, iii. 158.) 



Much more depends, than they who are not well accustomed to horses imagine, on 

 the length of the os calcis, or projection of the heck. In proportion to the leno;th of 

 this bone will two purposes be effected. The line of direction will be more advanta- 

 geous, for it will be nearer to a perpendicular, and the arm of the lever to which the 

 power is applied will be lengthened, and thus mechanical advantage will be gained 

 to an almost incredible extent. The slightest lengthening of the point of the hock 

 will wonderfully tell in the course of a day's work, and therefore it is that the char- 

 acter of the OS calcis is of such immense importance. 



The point of the hock is sometimes swelled. A soft, fluctuating tumour appears 

 on it. This is an enlargement of one of the mucous bags of which mention has been 

 made, and that surrounds the insertion of the tendons into the point of the hock. It 

 is termed, 



CAPPED HOCK. 



It is seldom accompanied by lameness, and yet it is a somewhat serious business, 

 for it is usually produced by blows and mostly by the injuries which the horse in- 



* These opinions of the seat and nature of obscure hock-lamcnnss arc now maintained b • 

 the majority of veterinary surgeons, aliliousih some of them differ a little with repard to 'he 

 articulation that is £rcnerally afiectpd, and tiio manner in which tlie dopresjions or excavations 

 on the surface of these hones is effected. In the loth volume of the ■''Veterinarian," are 

 some valuable observations on this subject by Professor Dick, and Messrs. Pritchard and 

 Spooner. 



