MORBID ANATOMY 319 



cultures guinea pigs die in from nineteen to thirty-one days 

 (Higgins) of generalized actinobacillosis. These are reported 

 to be characteristic and different from those of any of the 

 other observed infective agents. According to Higgins, 

 "Small pearly -white nodules appear just beneath the peri- 

 toneal and pleural membranes, varying from i.o to 5.0 mm. in 

 diameter. The liver presents lesions throughout its subtance, 

 the surface being mottled. The spleen shows, usually, a 

 varying number of nodules. The great mesenteric fold of the 

 omentum has in every instance been the seat of extensive 

 lesions. The kidneys present nodules beneath their serous 

 covering, but none have been observed in the substance of the 

 organ. The stomach and intestines usually present nodules 

 on their serous surfaces, varying from i.o to 0.5 mm. in dia- 

 meter." There are other lesions such as ulcers in the stomach, 

 nodules in the heart and pericardium. Subcutaneous inocula- 

 tions are usually followed by similar lesions. 



Rabbits are said to react the same as guinea pigs. Nocard 

 found an intravenous injection fatal to dogs in 24 hours. In 

 horses a local abscess resulted which healed rapidly. 



The method of infection has not been fully explained, but 

 it is supposed that the organisms are taken with food as in 

 cases of actinomycosis. 



The organisms are said to agglutinate in serum of animals 

 affected with actinobacillosis. 



It is destroyed in 10 minutes at 62° C. It grows best at 

 incubator temperature (37" C). It is not rapidly destroyed 

 by freezing. 



§ 240. Symptoms. They do not appear, in cattle, to 

 be differentiated from those of actinomycosis. 



§ 241. Morbid anatomy. The lesions are very similar 

 to those of actinomycosis. The location of the affected parts 

 varies. Ligni^res describes it as attacking the skin, lymphatic 

 glands, tongue, pharynx, mammary glands, the viscera and 

 bones. The tissue changes appear to be an infiltration of puru- 

 lent material, and the new formation of connective tissue. 



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