Equine myositis and septicemia caused by Acinetobacter calcoaceticus infection.

Myositis and septicemia caused by Acinetobacter calcoaceticus were diagnosed in a mare. The infection was characterized clinically by ventral swelling and edema, diarrhea, listlessness, and rectal temperature of 39.4 C. The mare was treated symptomatically for 2 days but died on the 3rd day. Conditions seen at necropsy were myositis, enteritis, typhlitis, colitis, and hepatitis. Lymph nodes were moderately enlarged throughout the body. Gross lesions in musculature were edema, scarring, petechiae, and an occasional exxhymosis. The enteritis was catarrhal, with excessive mucus and moderate hyperemia. The typhlitis and colitis were hemorrhagic. The swollen liver had a diffuse mottled pale and red pattern. Microscopic lesions in skeletal muscle consisted of petechiation, necrosis, scarring, and edema. Cardiac muscle was also scarred and necrotic, but edema was not prominent. Periacinal necrosis was found in the liver. Acinetobacter calcoaceticus was isolated from myocardium and liver.