978 



DISEASES OF THE LEG. 



violently drawn backwards, as in shoeing in the travis, or drawn 

 upwards by means of a cord passed through a ring. If, while the 

 foot is thus fixed, the animal fall, rupture is very apt to occur. It 

 may also be caused by efforts to withdraw the foot caught in railway 

 points, or even in deep, soft ground, and sometimes forms a sequel 

 to collisions, slips, or getting over bales. It seldom follows external 



violence, though a case is 

 recorded where the muscle 

 was divided by a sharp 

 stone. Klemm recom- 

 mended section of the 

 cunean branch of this 

 tendon in the treatment 

 of spavin. Rupture sel- 

 dom affects both limbs. 

 and is rare in animals 

 other than the horse, 

 though several cases are 

 reported in cows. In 

 dogs, the tendon which 

 corresponds to this muscle 

 may be divided as a re- 

 sult of external injuries. 



Symptoms. This rup- 

 ture is distinguished by 

 lameness when the limb 

 1 H is carried, marked flexion 



\H of the stifle-joints, and 



M excessive extension of the 



hock. The symptoms are 

 so marked that the con- 

 dition can be diagnosed 

 with absolute certainty, 

 even from a distance. As 

 the fibrous band stretch- 

 ing between the external 

 condyle of the femur and the metatarsus is no longer able to transmit 

 the movements of the femur to the metatarsus, and as the flexor 

 metatarsi muscle itself is powerless to make up for this deficiency, 

 the cannon bone is no longer flexed on the limb but hangs inertly, 

 and all the lower joints of the limb follow suit or are slightly 

 flexed. That portion of the limb below the hock is not properly 



Fig. 529. — Showing the mechanism of the hock 

 and stifle joints. The tendons of the flexor 

 metatarsi and gastrocnemius muscles unite the 

 bones forming the joints in such a way that they 

 are unable to move independently. 1, Ten- 

 dinous division of the flexor metatarsi muscle ; 

 2, 2', and 2", flexor perforatus ; 3. gastroc- 

 nemius tendon. 



