INFECTIOUS DISEASES OF MICE 



401 



enteritis. Deformity and ankylosis of affected joints occur and are visible 

 by roentgenological examination (301) (Figs. 154, 155, 156, 157). 



Pathological examination of the viscera reveals marked enlargement of 

 the spleen with numerous, often confluent, areas of necrosis throughout the 

 pulp. Similar lesions are found in the liver, though to a less extent. Con- 



FiG. 154. — .\rthritis and enlarge- 

 ment of right ankle joint in a mouse 

 naturally infected with Streptobacillus 

 moniliformis. {From van Rooyen. J. 

 Path, and Bad.) 



Fig. 155. — Infection with Strep- 

 tobacillus moniliformis. Mouse 

 showing edema of legs and tail. 

 {From van Rooyen.) 



gestion is present in the intestines with enlargement of the lymphatic struc- 

 tures. The kidneys and lungs are not affected. Involvement of the heart 

 is frequent and may vary from a serofibrinous pericarditis to a pancarditis. 

 Microscopically, endocarditis may be evidenced by small vegetations on the 

 valves and endocardium. The myocardium may show numerous foci of 

 inflammation, either acute or undergoing repair. Thrombosis of arterioles 

 and emboli of organisms in the capillaries occur. The articular and osseous 

 lesions vary from acute inflammatory to necrotic or proliferative processes. 



