242 HORSE, SWINE AND POULTRY DISEASES 



organized, leaving them in the form of a thick mass resting upon the 

 back part of the canon bone. 



KNUCKLING OF FETLOCK. 



As a consequence of the last-mentioned lesion of the tendons, 

 a new condition presents itself in the articular disposition, consti- 

 tuting the deformity known as the knuckling fetlock. By this is 

 meant a deformity of the fetlock joint by which the natural angle 

 is changed from that which pertains to the healthy articulation. The 

 first pastern, or suffraginis, loses its oblique direction and assumes 

 another, which varies from the upright to the oblique, from before 

 backward, and from above downward; in other words, forming an 

 angle with its apex in front. 



Causes. This condition, as we have seen, may be the result of 

 chronic disease producing structural changes in the tendons, and it 

 may also occur as the result of other affections or some peculiarity 

 independent of this and situated below the fetlock, such as ringbones, 

 sidebones, or traumatic disease of the foot proper. Animals are 

 sometimes predisposed to knuckling, such, for example, as are natur- 

 ally straight in the pasterns, or animals which are compelled to 

 labor when too young. The hind legs are more predisposed than the 

 fore to this deformity, in consequence of the great amount of labor 

 they are required to perform as the propelling levers of the body. 



Symptoms. The symptoms of knuckling are easily recognized. 

 The changes in the direction of the bones vary more or less with the 

 degree of the lesion, sometimes assuming such a direction that it 

 almost becomes a true dislocation of the pastern. The effect of 

 knuckling upon the gait also varies according to the degree of the 

 deformity. As the different degrees of the shortening of the leg 

 affect the motion of the fetlock, the lameness may be very slight or 

 quite extreme. Another consequence of this shortening is such a 

 change in the position of the foot that the heels cease to come in 

 contact with the ground and assume a greater elevation, and the 

 final result of this is soon witnessed in the development of a clubfoot. 



Treatment. To whatever cause the knuckling may be ascribed, 

 it is always a severe infirmity, and there is but little room for hoping 

 to overcome it unless it be during the very first stages of the trouble, 

 and the hope dwindles to still smaller dimensions when it is second- 

 ary to other diseases below the fetlock. If it is caused by overwork- 

 ing the animal, the first indication will, of course, be rest. Line fir- 

 ing has proved very efficacious in these cases. The animal must be 

 turned loose and left unemployed. Careful attention should be 

 'given to the condition of his feet and to the manner of shoeing, 

 iwhile time is allowed for the tendons to become restored to their 

 normal state and the irritation caused by excessive stretching has 

 subsided. A shoe with a thick heel will contribute to this. But if 

 no improvement can be obtained and the tendons though retracted 

 [have yet been relieved of much of their thickening, the case is not a 

 desperate one, and may yet be benefited by the operation of tenotomy, 

 single or double an operative expedient which must be committed 

 to the experienced surgeon for its performance. 



