214 DISEASES OF THE JOINTS. 



known by those skilled, but little recognised generally by the 



profession Eheumatoid arthritis appears to be a 



disease arising from exposure to cold and damp, but only in a 

 person constitutionally predisposed by debility from some cause 

 or other. But, truly, we know nothing certain in regard to this, 

 and we require to have our knowledge of human pathology col- 

 lated with that of the horse before we can form any rational 

 theory on the subject. The blood, the urine, and the perspira- 

 tion have all been analysed with merely negative results, and 

 yet the morbid anatomy of the disease is perhaps the richest and 

 the most extraordinary belonging to any complaint, the disease 

 affecting, in its peculiar way, every bone and every joint in the 

 body. In the early stage of the disease, there is found simply 

 effusion of synovia, with vascular injections, signs of arthritis ; 

 at a later stage the fluid becomes absorbed, the capsular mem- 

 brane thickened, and the cartilage ulcerated. At a very early 

 period this cartilage splits up, and becomes removed apparently 

 by a slow process of absorption, the whole surface of the joint 

 being then denuded, the osseous surface becoming polished and 

 eburnated, as in those specimens." 



The treatment is merely palliative, and is chiefly constitu- 

 tional. Alkalies may be administered, the bowels regulated b} 

 an occasional purgative, the animal carefully fed, and put to 

 slow work ; and when any sudden increase of lameness, denot- 

 ing a fresh attack, occurs, fomentations, or perhaps moderate 

 blisters, are to be prescribed. 



MORBID CONDITION OF CAETILAGE. 



Articular cartilage becomes diseased in consequence of syno- 

 vitis, disease of the bone to which it adheres, or independently 

 of any morbid condition of adjacent structures, and such disease 

 may commence upon its free or its attached surface, or in the 

 middle of its substance. 



In violent inflammation of joints, as those arising from punc- 

 ture, the destruction of the cartilage is accompanied, or even 

 preceded, by the destructive absorption of the vascular extremity 

 of the bone immediately contiguous to its articular laminal layer. 

 In this manner we can explain the presence of floating pieces of 

 cartilage and bone in the synovial fluid. 



