66 LAMENESS IN THE HORSE. 



sound oue. It is also advisable to take up the foot and 

 extend it, at the same time pushing the toe upward, thereby 

 exerting an extra strain upon the liganientous apparatus of 

 the diseased parts. The sound leg should be manipulated 

 in the same way, and the results compared ; in this way 

 errors are better avoided. 



Differential Diagnosis. — This lameness resembles laminitis 

 somewhat, but in the latter one finds excessive pulsation in 

 the digital arteries, which is absent in inflammation of the 

 posterior ligaments of the coronary joint. It differs from 

 chronic navicular disease by the fact that contraction of the 

 hoof and pain on compressing the horny box, over the 

 region of the navicular bone, are wanting. (See page 76). 



4.— Sesamoid Lameness. 



History. — Lameness following anything straining the 

 flexor apparatus excessively, as jumping, or stopping a horse 

 suddenly when going fast, etc. 



Inspection: Acute Form. — The animal, at rest, points 

 forward, with the phalanges in volar flexion. There is 

 supporting-leg lameness. 



Palpation. — More or less swelling and pain over the 

 region of the sesamoid bones. 



Inspection : Chronic Form. — Forward pointing, with 

 marked volar flexion of the phalanges when the animal 

 stands quietly, is met with. There is supporting-leg 

 lameness, more pronounced when first starting out, 

 increasing on rough ground, and decreasing on prolonged 

 rest. In severe cases, the horse is even lame at a 

 walk. Permanent volar flexion of the fetlock, combined 

 with swelling of the perforans tendon, is found where this 

 lameness is of long standing. 



