Septic cholangiohepatitis and cholangiocarcinoma in a horse.

The researchers investigated an 11-year-old Warmblood gelding horse exhibiting signs of septic cholangiohepatitis and intermittent fever and colic. Despite initial treatments, the horse’s condition worsened, and its disease developed resistance to gentamicin, resulting in the formation of hyperechoic structures indicative of biliary calculi. The horse was euthanized due to severe lameness and fever, and post-mortem examination revealed hepatocarcinoma and metastasis to the right metacarpophalangeal joint. The study suggests that veterinarians should consider the possibility of carcinoma in cases of septic cholangiohepatitis that do not respond to antibiotics.

Case Presentation and Initial Diagnosis

• The subject of the research was an 11-year-old Warmblood gelding horse who was displaying signs of intermittent colic and fever.
• An initial diagnosis of septic cholangiohepatitis was made. The bacteria causing the infection, Klebsiella pneumoniae, was found to be susceptible to the antibiotic gentamicin.
• Despite this diagnosis and treatment plan, the horse’s condition failed to significantly improve.

Treatment Resistance and Disease Progression

• Three weeks later a second biopsy was taken, showing that the hepatic inflammation had progressed. This time, the K pneumoniae had developed resistance to gentamicin.
• Ultrasonography revealed several discrete hyperechoic structures in the liver, suggesting the presence of biliary calculi (gallstones).
• Changing the antibiotic treatment led to a gradual resolution of the clinical signs, albeit temporarily.

Further Complications, Final Diagnosis, and Outcome

• Despite a temporary reprieve, the horse suffered a sudden onset of severe right forelimb lameness five months after initial examination.
• Seven months later, the horse had to be euthanized due to recurrent fever and lameness that did not respond to treatment.
• Post-mortem examination revealed the presence of carcinomatous nodules throughout the liver and a related mass in the right metacarpophalangeal joint.
• It was concluded that the horse had been suffering from a form of hepatocellular carcinoma originating from the biliary epithelium, which had metastasized to the skeletal system.
• The study therefore suggests considering carcinoma as a potential diagnosis in cases where septic cholangiohepatitis does not respond to treatment.