.LAMENESS, FROM VARIOUS CAU&riri. 337 



The authorities teach us, and my own experience has confirmed 

 the fact, that iodide of potass is a valuable agent in the treatment 

 of chronic rheumatism. It is most sure to act beneficially when 

 the periosteum (fibrous covering of the bones) is affected. There 

 is no doubt that chronic rheumatism often cripples the joints by 

 producing disease of the bones in the region of their articulations. 

 This makes a poor horse dead lame, and renders him almost useless. 

 When the bones become ulcerated or carious there remains but little 

 hope of cure. 



Ring-bone. 



Ring-bone is a form of disease the pathology of which is similar 

 to that of spavin and splent. It is located just above the coronet 

 or crown of the hoof. The enlargement is called exostosis (a mor- 

 bid enlargement of bone), and when the large pastern becomes 

 united to the smaller one, the case is called anchylosis (permanent 

 rigidity of the joint). 



The term ring-bone is far behind the times as regards our pres- 

 ent knowledge of nosology (the doctrine of the names of diseases) ; 

 yet, to the unprofessional, it is suggestive, and, therefore, we are 

 compelled to retain a name which all can interpret. It signifies 

 a complete or partial eminence around pastern bones. The ring 

 is formed by incrustations, or osseous deposits in the pastern, or 

 involving the joint, as the case may be; yet, in order to make out 

 a pure case of ring-bone, that comes strictly within the meaning 

 of the term as horsemen interpret it, there must exist a complete 

 ridge of bone around the anterior part, extending from side to side. 

 A pure case of ring-bone generally originates on the surface of the 

 bone, on or beneath the periosteum. Commencing at the lower 

 margin of pastern and upper part of the coronet bone, the disease 

 spreads, involving both capsular ligament and joint. The remote 

 cause of ring-bone lies in hereditary idiosyncrasies, transmitted 

 through the sexual congress. The disease itself is sometim3s di- 

 rectly transmitted. I once bought an un weaned colt, and brought 

 it up by hand. A short time after purchase, I observed enlarge- 

 ments on the hind pasterns. He ultimately turned out to be a 

 ring -boned animal, and had stiff joints. I found out afterward 

 that the mother had' large ring-bones on both hind pasterns. The 

 disease was, therefore, congenital. 



Mr. Percivall, whose opinion on such matters is unquestiou 

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