SEPTIC CHOLANGIOHEPATITIS AND CHOLANGIOCARCINOMA IN A HORSE

Septic cholangiohepatitis was diagnosed in an 11-year-old Warmblood ge lding with a history of intermittent colic and fever. Klebsiella pneum oniae, susceptible to gentamicin, was cultured from the biopsy specime n. However, treatment with gentamicin was unsuccessful, and histologic examination and bacteriologic culture of a biopsy specimen obtained 3 weeks later revealed progression of the hepatic inflammation and yiel ded growth of gentamicin-resistant K pneumoniae. At this time, several discrete hyperechoic structures, suggestive of biliary calculi, were seen ultrasonographically. A change in antibiotic treatment was associ ated with gradual resolution of clinical signs. Five months after init ial examination, the horse had a sudden onset of severe right forelimb lameness. The horse responded to treatment with antibiotics and pheny lbutazone, but lameness and fever that was unresponsive to treatment r ecurred 7 months later, and the horse was euthanatized. Necropsy revea led nodules throughout the liver and a mass associated with the right metacarpophalangeal joint. Histologic and immunohistochemical examinat ion revealed carcinomatous infiltration of the liver and metacarpophal angeal joint. The tumor was probably of biliary origin. Carcinoma shou ld be considered in cases of septic cholangiohepatitis unresponsive to antibiotic treatment.