PREVENTION AND TREATMENT OF RING-BONE. 



885 



last resource, those more commonly performed will be described at 

 this place. 



Before utilising any of these operations, however, it is necessary 

 clearly to ascertain two points— viz. : (1) That the diseased and 

 painful parts are exclusively supplied with sensory fibres by the 

 nerve to be divided ; and (2) that the lameness is due solely to pain 

 and not to such changes as adhesions in or around the joints them- 

 selves or contraction of tendons or ligaments. If these conditions 

 can be satisfied the lameness will be removed by neurectomy, but 



Fig. 502. — Neurectomy below the fetlock. A, Ligament of the ergot ; B. digital 

 nerve ; C, digital artery. 



not otherwise. Needless to say, it is unwise to operate on riding- 

 horses, especially when the front limbs are placed far under the body 

 and the pasterns are upright ; such animals are prone to falls under 

 any circumstances, and to deprive them of sensation in the lower 

 part of the limb is calculated to aggravate the defect. 



Plantar neurectomy. This operation may be performed at one of 

 several points : one to two inches above the sesamoid bone, where 

 the nerve lies immediately in front of the flexor tendons ; on the 

 lateral surface of the fetlock-joint, or, again, an inch or so below 

 the sesamoid bone and behind the fibrous band which extends from 

 the plantar cushion to the ergot. Resection of the nerves at or 

 above the fetlock is known as high plantar neurectomy, while 



