Medical and surgical management of an intra-abdominal abscess of hepatic origin in a horse.

CASE DESCRIPTION: A 4-year-old Arabian-cross mare was examined because of a 48-hour history of pyrexia, lethargy, and signs of abdominal discomfort. CLINICAL FINDINGS: On initial evaluation, the horse was in good body condition, but febrile, tachycardic, tachypneic, and icteric and had signs of colic. Findings on CBC and serum biochemical analysis indicated marked systemic inflammation and hepatocellular damage. Serial abdominal ultrasonographic examinations revealed progressive, localized hepatic parenchymal abnormalities in the left ventral aspect of the abdomen in proximity to the left liver lobes, and eventual identification of an irregularly marginated, hyperechoic walled region of heterogenous echogenicity consistent with an encapsulated hepatic abscess. TREATMENT AND OUTCOME: Medical treatment was initiated with administration of doxycycline and flunixin meglumine. After 7 days, the horse's clinical signs and hematologic values improved. After 14 days, the horse was discharged from the hospital and prescribed continuation of doxycycline treatment for 14 days. One week following hospital discharge, the horse was reevaluated for recurrent signs of colic and pyrexia. The horse was sedated, and the region overlying the caudal aspect of the seventh rib was desensitized with an inverted L nerve block by local infiltration with 2% lidocaine. While the horse was standing and sedated, drainage of an encapsulated intra-abdominal abscess was followed by rib resection and removal of a portion of necrotic left lateral liver lobe. The development of a pneumothorax following rib resection represented the only major surgical complication. Twelve months later, the horse was clinically normal and had returned to its previous level of performance. CLINICAL RELEVANCE: Rib resection in standing sedated horses, together with appropriate medical management, should be considered an option for removal of well-encapsulated cranially located intra-abdominal abscesses that are adherent to the ventrolateral aspect of the body wall in horses.