250 DISEASES OF BONE. 



is the term usually applied when the deposit involves the joint 

 which is between the long and short pastern bones. This is more 

 common than the next variety, and may be readily seen in the 

 form of a swelling on the front of the pastern. (Fig. 87). A very 

 severe case of this form of ringbone, with complete bony union 

 between the two pastern bones is shown in Fig. 92. (3) Loiv 

 ringbane, when the bony formation affects the joint between the 

 pedal bone and the short pastern bone. This is far more serious 

 than the first two, owing to the unyielding nature of the horny 

 wall of the hoof which surrounds the implicated joint. Both high 

 and low ringbone may be due to an inflammation which leaves 

 the articular cartilages of the affected joints intact; or, according 

 to Schrader, Moller, and other German writers, to rheumatoid 

 arthritis (p. 269). Fig. 117 shows a case of ringbone from fracture. 



These bony deposits are usually confined to the front and sides 

 of the bones, and have a tendency to surround these parts. If 

 they extend to the back of the joints, they will give rise to in- 

 tractable lameness. As a rule, they are probably due to com- 

 pression of the pastern bones, especially in the hind legs, or to 

 sprain of the ligaments of the pastern joints. The symptoms 

 may somewhat resemble those of " split pastern " (p. 302). King- 

 bones are more common on the hind, than on the fore feet, 

 though the opposite is the case with sidebones. This difference 

 is probably due to the fact that, in the hind feet, more work is 

 thrown on the toe, than in the fore feet. I may here remind my 

 readers that the lateral cartilages (p. 276) are situated on the sides 

 and back of the foot; and that the front of the pasterns is the 

 usual seat of ringbone. I have seen, on different occasions, cases 

 of lameness from ringbone which had been induced by the horse 

 " going on his toe," owing to a previously existing spavin. If 

 concussion were a common cause of ringbone, that disease, con- 

 trary to what is actually the case, would appear more often in 

 the fore legs than in the hind. 



We should not reject a horse because his pasterns are " rough," 

 that is, large and with prominent processes of bone for the attach- 

 ment of tendon and ligament; as this is the best shape, always 

 supposing that both pasterns are the same. 



I have seen several cases of foals and yearlings having been 

 treated for ringbone ; although their i)asterns and feet were free 

 from disease. In these young animals, as explained by Moller, a 

 false appearance of ringbone is often shown, on account of the 

 comparatively large size of the heads of the pastern bones, and 

 the incomplete development of the hoof. 



In the early stages of ringbone, a horse becomes lame before 

 any deposit is formed or any swelling takes place ; for, here, the 



