Q72 ACTINOBACILLOSIS 
ter. The liver presents lesions throughout its substance, 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 1.0 to 0.5 mm. 
in diameter.”’ There are other lesions such as ulcers in the stomach, 
nodules in the heart and pericardium. 
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 i in 10 minutes at 62° C. It grows best at ae 
temperature (37° C.). It is not rapidly destroyed by freezing. 
Symptoms. They do not appear, in cattle, to be differentiated 
from those of actinomycosis. 
Morbid anatomy. The lesions are very similar to those of actino- 
mycosis. The location of the affected parts varies. Ligniéres 
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 purulent material and the new formation of 
connective tissue. The skin is often affected. In the single specimen 
which the writer has had an opportunity to study, the ray-like arrange- 
ment of the organism and the tissue immediately surrounding it 
could not be easily distinguished from a section of actinomycosis. 
The possibility of a double infection with the bacterium and the ray- 
fungus does not seem to have been carefully investigated. 
Diagnosis. Actinobacillosis is to be diagnosed by finding the 
bacterium and the ray-fungus or the ray-fungus-like organisms. It 
is to be differentiated from actinomycosis, tuberculosis, perhaps cer- 
tain parasitic diseases of the skin, and localized bacterial infections. 
The diagnosis is assisted by the fact that the lesions are most often 
found in the skin. The examination of the fresh pus does not reveal 
the yellow granules as observed in actinomycosis but when squeezed 
