Feline Hepatic Disease (Cholangitis/Cholangiohepatitis)

Feline Inflammatory/Infectious Hepatic Disease

Neutrophilic Cholangitis/Cholangiohepatitis

• More common in cats than dogs
• Proposed pathogenesis is ascending bacterial infection
• Characterized by neutrophils within the bile duct lumen, associated with the bile duct or between biliary epithelial cells
• Inflammation extending beyond the limiting plate and into the hepatic parenchyma is diagnosed as cholangiohepatitis
• Many cats have normal liver enzyme values, but about 2/3 are hyperbilirubinemic
• Imaging findings: hyperechoic hepatomegaly, bile duct or gallbladder distension, gallbladder sludge, and GI tract abnormalities
• Consider AUS-guided FNA, but note the limitation of small sample size
• Preferred diagnostic method: 16-gauge US-guided needle bx or surgical wedge bx or laparoscopic liver bx
• Bleeding is a common complication of biopsy, regardless of coagulation status
• Anaerobic and aerobic culture is important in cats with hepatobiliary disease
• Common isolates: E. coli, Enterobacteriaceae, Streptococcus, Enterococcus, Actinomyces, Acinetobacter, Pasteurella, Clostridium, and Bacteroides species
• Treatment involves antibiotics active against aerobic and anaerobic bacteria, and nonspecific treatments for nausea, reduced appetite, dehydration, HE, and lowering gastric acid production

Lymphocytic Cholangitis

• Gradual weight loss, vomiting, lethargy, and decreased appetite are common symptoms
• Immune-mediated mechanism proposed, with possible role of Helicobacter and Bartonella
• Histologically characterized by dense aggregates of lymphocytes surrounding bile ducts
• When infectious causes are ruled out and/or cats fail to respond to antibiotics, immune suppressive therapy (prednisolone) is recommended

Infectious Hepatobiliary Diseases

• Bacterial component more common in neutrophilic cholangitis
• Hepatic abscesses with Klebsiella, Listeria, Salmonella, Brucella, Actinomyces, and Nocardia
• Mycobacterium infection: histopath reveals extensive granulomatous disease
• Platynosomum infection: chronic cholangitis associated with liver fluke infestation from the platynosomum group
• Tropical and subtropical regions are affected
• Adult flukes in the bile, liver, and gallbladder cause biliary obstruction
• Cats likely acquire the parasite by eating infected lizards
• Treatment: praziquantel

Viral Infections

• FeLV: associated with hepatic neoplasia, fatty liver, and hepatic necrosis
• Calicivirus: viral mutants can cause hepatic infections, with disseminated hepatocellular necrosis and mild inflammatory infiltration
• FIV (lentivirus): associated with cytopenias and cancer, rarely causes hepatic disease with general degradation or peribiliary fibrosis
• FIP: hyperbilirubinemia is common, but may be due to RBC destruction; livers frequently have histologic FIP, granulomatous lesions

Fungal Infections

• Histoplasmosis: the second most common systemic fungal disease in cats and the most common hepatic fungal disease
• Treatment: Itraconazole (5-10 mg/kg PO q12) for a minimum of 4-6 months

This quiz covers feline inflammatory and infectious hepatic diseases, including neutrophilic cholangitis and cholangiohepatitis. Learn about the proposed pathogenesis, histological features, and diagnosis of these diseases in cats.