204 THE HORSE IN HEALTH AND DISEASE 



bones of the articulation become firmly welded together, the joint 

 is said to be ankylosed and a stiff, immovable articulation results. 

 A dull, continuous pain is always present in ostitis. The most 

 satisfactory treatment is the counterirritant either applied as a 

 blister or the actual cautery. 



Osteomyelitis is inflammation of the bone-marrow. It is a 

 serious disease, but fortunately is relatively rare. Suffice it to say 

 that infectious forms of osteomyelitis are usually incurable. 



From a practical point of view there are three forms of inflam- 

 mation of bone which deserve especial mention. They are bone 

 spavin, ring-bone, and splints. Usually they all cause an exostosis 

 to appear at the seat of the inflammation. Each reduces the value 

 of the horse for both work and breeding purposes, but not in the 

 same degree. When considered in order of importance they should 

 be ranked as mentioned above, for spavin is a more serious disease 

 than ring-bone, which, in its turn, incapacitates the horse to a much 

 greater extent than does a splint. 



BONE SPAVIN 



Bone spavin is the term applied to the exostosis that occurs 

 on the inner side and in front of the hock-joint (Fig. 59). There 

 are three kinds or forms of spavin — viz., (1) high or "true spavin," 

 which is the most serious; (2) low or "jack spavin," which does not 

 interfere to such an extent with the joint; (3) occult or "blind 

 spavin," which involves the joint surfaces, presents no enlargement, 

 but is accompanied by marked lameness. 



The causes of bone spavin are those things which excite the tis- 

 sues to inflammation — for example, a hereditary tendency from the 

 sire or dam; faulty conformation ; mechanical injuries to the hock, 

 either from blows or kicks or from too rapid and hard work on 

 paved streets; excessive strain upon the hock-joint from improper 

 shoeing. 



Symptoms. — Lameness is the first symptom noticeable. The 

 horse avoids moving the joint and develops a characteristic 

 "spavined gait," in which a slight hitch is observed in the hip on 

 the affected side and a decided dropping of the opposite hip. 

 This is most pronounced when the horse first starts, and results 

 from throwing the weight of his body upon the sound leg. When 

 driven a short distance he "warms out" of the lameness. After he 



