272 DISEASES OF THE BONES AND ARTICULATIONS. 



all conditions. In acute cases of suppuration of the joints the 

 cartilage may be softened, perforated, or partially destroyed, so 

 that the bone is bare in some places. In many chronic cases of 

 inflammation of the joints the cartilage becomes macerated and 

 dissolved into fibres, or it may be overgrown ¥/ith abnormal syn- 

 ovial extensions. As soOn as the bone proper becomes involved 

 in the inflammatory process extensive granulations form, causing 

 a peculiar spongy growth. These crowd and perforate the bone 

 here and there, and also affect a cartilage of the opposing bone, 

 leading to a cicatricial growth on the end of the joint. In some 

 cases we also see the fibres and cells of the cartilage becoming 

 soft and finally growing up with numerous raised cartilaginous 

 cells, and an acute inflammation of the ends of the joints. From 

 these periodical conditions we may have a marked alteration in 

 the form of the joint. Edges of the joint protrude, the inner 

 surface being hollowed and grooved. A peculiarity of deforming 

 inflammation of the joints is an inflammation of the synovial mem- 

 brane, with a normal excretion of synovia and a great enlargement 

 of the free or loose portion of the membrane which may develop 

 into papilla-shaped masses. 



The bone, as a rule, does not become affected in acute inflam- 

 mation of the joint; but if it should become uncovered from suppu- 

 ration of the cartilage, the inflammation extends to the spongiosa, 

 and we see occasionally the formation of purulent or granular 

 centres on the surface. In rare cases the periosteum becomes 

 covered with osteophytes. 



In tubercular diseases the joints of the dog may become diseased, 

 but as yet such cases have not been demonstrated in veterinary 

 literature. 



Acute Synovial Inflammation of the Joints. 



(Synovitis Acuta Serosa. ) 



The joint is swollen and hot, and the animal shows pain on 

 pressure or movement of it. These symptoms indicate an inflam- 

 mation of the synovial membrane and a lessening of the secretion 

 of synovial fluid into the joint. It is very rare that we see intense 

 fibrinous excretions (synovitis sero-fibrinosa), and still more rare 

 are those cases of colorless blood-cells mixed with detached epi- 



