[Bacterially conditioned thromboembolism in dairy cows--a retrospective study of 31 necropsy cases with special consideration of the causative complex].

A study of 340 necropsied dairy cattle from northern Bavaria resulted in 31 animals (9%) showing evidence of pyemic thromboembolism. The most frequent pathomorphologic lesions consisted in endocarditis valvularis thromboticans of the tricuspid and/or mitral valve (21), embolic pneumonia (26), nephritis (13) and renal infarction (12). The most common isolate found in bacteriologic culture was Arcanobacterium pyogenes in 26 of 31 cases, followed by Staphylococcus aureus (2), Mannheimia haemolytica (2) and Streptococcus bovis (1) in rare cases. In 27 of 31 cows a possible cause of pyemic thromboembolism was found; in 23 cases claw diseases and decubital ulcera were probably responsible.