Contribution to the pathology of anaplasmosis in cattle

Abstract

The anatomical lesions and histopathology of bovine anaplasmosis were studied in 69 animals dying of the infection. Of these 54 were European type animals which succumbed following injections of ice-box cooled blood from Anaplasmosis-carrier cattle. The other 15 animals were Brazilian born with the infection ascribed to tick bites. In the injected animals 53 of the 54 showed splenomegaly, an increase in both volume and weight; 32 animals showed hepatic icterus and there 32 cases of petechial hemorrhages on the epicardium; 21 showed general icterus and in 16 cases the gall bladder was distended by a thick, fluid bile. In the naturally infected animals splenomegaly was the most common lesion found in 10 of 5 animals; anemia and thickening of the bile were present 6 cases each and hepatic icterus in 4 cases. Secondary lesions of bronchopneumonia were seen in 10 of 54 injected animals and 7 of those infected by ticks. Histopathological studies of the liver, spleen and bone marrow were made of several animals. The most common lesions were hepatic steatosis frequently associated with centrilobular necrosis showing filamentous aspects. In the spleen there was congestion of the red pulp anti atrophy of the white pulp. The bone marrow consisted almost exclusively of erythroblastic elements with no leucoblastic elements present.