206 THE HORSE IN HEALTH AND DISEASE 



standing he frequently rests the heels of the diseased leg on the 

 wall of the opposite foot for relief. 



To determine the presence and severity of a spavin the animal 

 may be subjected to the spavin or hock test. This is made by 

 flexing the joint for at least a minute by grasping the lower end of 

 the cannon with the hand and closing as completely as possible the 

 angle formed by the leg and cannon bones. Immediately the ani- 

 mal is made to trot briskly away from the examiner. If a spavin 

 is forming, the horse will show the peculiar lameness described 

 above. 



Treatment. — In treating a bone spavin the object aimed at is 

 to hasten nature's effort toward ankylosis or union of the diseased 

 bones. This requires transforming the existing chronic inflamma- 

 tion into the acute form. To accomplish this end more blood must 

 be brought to the part. The application of blisters or the firing-iron 

 are the means used to bring it about. Point firing, or the introduc- 

 tion of a red-hot pointed firing-iron through the skin into the bone 

 tissue, is resorted to if the blister fails. Rest is an important ad- 

 junct to the treatment and is necessary for complete ankylosis. 

 The horse should be shod with a high-heeled shoe to take the strain 

 off the front of the joint. 



RING-BONE 



Ring-bone, like bone spavin, results in an exostosis, but occurs 

 in the region of the large and small pastern bones (Fig. 60). The 

 bones of the fore limbs are more frequently affected than those of 

 the hind. There are unilateral and bilateral, highland low, and 

 articular and non-articular ring-bones, depending on their exact lo- 

 cation and extent. The causes are most often mechanical and are 

 similar to those of spavin. Long sloping, or short upright pasterns, 

 predispose to ring-bone formation. Lameness is the most evident 

 symptom. Later, a hard swelling develops, over which the skin 

 is freely movable. The horse "points" when standing and shows 

 a well-marked stiffness when moving. 



Treatment will depend on the character of the ring-bone; gener- 

 ally it is the same as for spavin. Here, as in similar cases where the 

 actual cautery is applied, it must be deferred until acute inflam- 

 mation has subsided. By trimming colts' feet regularly, and shoe- 

 ing older horses so as to straighten the foot's axis, many cases can 

 be prevented. As a last resort neurotomy may be tried. 



