Hepatic abscesses in three horses.

Hepatic abscesses were diagnosed in 3 adult horses. Two were < 4 years old and had evidence of concurrent immune-mediated conditions, including aseptic arthritis, immune-mediated thrombocytopenia, and immune-mediated anemia. Predisposing factors for hepatic abscess formation in these horses included prior abdominal surgery, proximal duodenitis/jejunitis, inflammatory bowel disease, and a penetrating foreign body in the large colon. Serum hepatic enzyme activities were within or slightly greater then reference limits in all 3 horses. The most pronounced and consistent abnormalities on CBC and serum biochemical analyses were hyperproteinemia, hyperglobulinemia, and a decreased albumin-to-globulin concentration ratio. Hepatic ultrasonography identified hepatic abscesses in all 3 horses. A variety of bacteria were isolated from these abscesses, including Staphylococus aureus and Bacteroides fragilis. One horse developed septic tibiotarsal arthritis, presumably as a result of intermittent bacteremia. Despite aggressive medical treatment, all horses were euthanatized because of a worsening condition and poor prognosis.