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RINGBONE. 



The disease we are about to treat on will be found to be another 

 form of exostosis, or rather exostosis in another situation, and can 

 only be regarded as " a disease of joint " in so far as it has con- 

 nexion, director indirect, with any joint ; though this will be found 

 to be generally the case whenever lameness is a consequence, and 

 sometimes where such is not perceptible. 



Definition. — The appellation of ringbone is applicable to any 

 osseous tumour upon the pastern bone, but with the greatest pro- 

 priety to that which takes on the form of a ring round the bone 

 a shape which any continuous osseous deposit is Ukely to assume 

 from the circumstance of its substratum being the rotund surface 

 of a cylinder. 



The ordinary Site of Ringbone is the pastern bone. It is 

 possible, however, but a rare occurrence, for it to be confined to 

 the coronet bone. It occurs more frequently upon the hind than 

 upon the fore leg. And mostly we find the tumour approximating 

 the pastern joint ; and where such is the case, and the deposition 

 of callus proceeds, we perceive the tumefaction gradually creeping 

 over this joint, involving as well the bones above and below, 

 more or less, in the disease. Sometimes the tumour occupies the 

 middle of the pastern bone, having no immediate connexion with 

 any joint. Rarely is it seen sufficiently high upon the pastern to 

 disturb the fetlock-joint. 



Kinds of Ringbone. — These various sites of exostosis have 

 given rise to distinctions into high ringbone and low ringbone ; the 

 latter being the common or ordinary kind. Such distinctions, how- 

 ever, can serve little practical purpose, save in so far as, being high 

 or low, the ossification involves the pastern or fetlock-joint in its 

 spread, and implicates the cavity of the joint in the disease. It 

 is any thing but uncommon to see the pastern joint in a state of 

 anchylosis from ringbone ; and in the different veterinary museums 

 preparations enough will be found of the coffin joint from the spread 

 of ossification being anchylosed as well. Any portion, however, 

 of the exostosis which might occupy the lower half of the coronet 

 bone would be included within the coronary substance (or coronary 



