UDDER-STREPTOMYCOSIS 43 



unaltered or shows an oedematous swelling. If it runs a 

 longer course the spleen is very large, and the liver may 

 show small multiple areas of necrosis or abscesses and the 

 point of inoculation, local necrosis with abscess formation. 



The animals usually die of bacter^emia, although they 

 may also die of septic intoxication without bacteraemia. 



In bacteraemia the number of streptococci is small but 

 they are comparatively numerous in the spleen pulp. 



Dogs, — These animals are also quite susceptible to the 

 infection. One c.c. of a bouillon culture injected subcu- 

 taneously can kill the animal in one to five days, depending 

 upon the virulence. 



Autopsy. — If death occurs very suddenly the cadaver 

 shows spleen swelling, serous extravasation into the ab- 

 dominal and thoracic cavities and into the pericardial sac, 

 lung oedema and a local oedematous swelling at the point 

 of inoculation. If the course be more protracted we may 

 find a serofibrinous peritonitis, pleurisy and (or) peri- 

 carditis and not infrequently serofibrinous arthritis and 

 pneumonia. 



As a rule the animals die of bacteraemia. Great num- 

 bers of bacteria are found in the spleen pulp. If they do 

 not die of bacteraemia the organisms are found in great 

 numbers in local nodules. 



Pigeons are somewhat resistant to the infection. They 

 may be killed however in from one to two days by intra- 

 muscular injection of one c.c. of a highly virulent culture. 



Autopsy. — A serous exudate is found in the abdom- 

 inal cavity and the pericardial sac. The blood is rich in 

 streptococci. 



Ghdnea-pigs are very resistant to the infection. One c.c. 

 of a highly virulent culture injected subcutaneously in a 

 guinea pig only produces local necrosis at the point of 

 inoculation with abscess formation. The animal does not 

 die. 



