258 DISEASES OF BONE. 



cases, and especially in occult spavin, the lameness " consists in a 

 sort of spasmodic catching up of the spavined limb the moment 

 the heel of the foot comes down upon the ground, something after 

 the manner of stringhalt " (Percivall). At times, the stiffness 

 can be observed only when the animal is pushed over from one side 

 to the other in his stall. A spavin may often be detected when 

 riding a horse down a steep hill, from the fact of his " dragging the 

 toe.'^ " The time of all others when a spavined horse will be apt 

 to manifest his lameness will be the day following after a hard day^s 

 work; and when he m.akes his first egress from the stable in the 

 morning is the critical period for examination " (Percivall). There- 

 fore, we should be prepared to form our judgment quickly in these 

 cases; for the longer the animal is trotted up and down the 

 less lame will he generally become. At the end of each trot 

 past, he should be turned a different way; for instance, first to the 

 left about, then to the right about, so that we may see on which 

 hind leg he turns best. If there still be a doubt, the foot of the sus- 

 pected leg may be taken in the hand, drawn upwards and held (Fig. 

 2), so that the hock may be kept bent for a couple of minutes, and 

 then the foot may be let down. If spavin is present, lameness 

 will become very apparent, if, after that, the horse be trotted. 



We may have the visible sign of spavin — swelling at, and hard- 

 ness of the part — without lameness. If there be heat and tender- 

 ness on pressure, lameness will almost certainly be present. A 

 careful comparison by the eye should be made of both hocks. If 

 they are found to be exactly similar and no trace of lameness is 

 present, the horse may be passed as all right. The observer while 

 standing close to the side of its respective fore leg, should view 

 each hock, a,nd should see if there be the slightest difference be- 

 tween the two hocks, or abnormal prominence on the site of spavin 

 of either. " Now it is precisely the interval between the promi- 

 nence of the hock ceasing and the cannon beginning — the part of 

 the superficial line which constitutes the dip from one into the 

 other — that is the site of spavin ; a small round tumour interrupts 

 the natural declivity from the hock to the cannon, and in a moment 

 catches the eye of the experienced observer. In cases where the 

 tumour, from its smallness or flatness, or diffuse character, is in- 

 distinct to the eye, the examiner will not make his mind up con- 

 cerning it until he has narrowly compared the suspected with the 

 sound or nomial hook" (Percivall). See Figs. 93, 96 and 97. He 

 should satisfy himself by feeling both hocks, the near with the 

 right, the oft' with the left hand. A more correct impression is 

 conveyed by a light and moderately rapid touch, when running the 

 hand down, than by dwelling long and pressing hard. 



The existence of a spavin in the form of a small point of bone, 



