Hepatic Lipidosis

Hepatic lipidosis (HL) is the most common feline liver disease. It occurs when a cat — typically overweight — undergoes a period of anorexia or reduced food intake. The body mobilizes peripheral fat stores faster than the liver can process them, leading to massive triglyceride accumulation in hepatocytes and subsequent hepatic dysfunction.

Risk factors:

• Obesity (primary risk factor)
• Anorexia > 3–5 days (stress, illness, diet change, environmental change)
• Concurrent disease (pancreatitis, CKD, GI disease, diabetes)
• Primary hepatic disease (cholangiohepatitis)

Clinical signs: Anorexia, lethargy, vomiting, icterus (sclera, mucous membranes, skin), weight loss, muscle wasting, hepatomegaly, dehydration, bleeding tendencies.

Chemistry:

• Marked ALT and AST elevation (often > 500 U/L)
• Hyperbilirubinemia (often > 5 mg/dL)
• Hypokalemia, hypophosphatemia (refeeding risk)
• Hypoproteinemia (especially albumin)
• Coagulopathy: prolonged PT/PTT; vitamin K responsive

Ultrasound: Diffuse hepatomegaly with increased echogenicity (bright liver). Rules out biliary obstruction, masses.

Fine-needle aspirate (diagnostic): Lipid-laden hepatocytes with small, peripheral nuclei. Safe and minimally invasive.

Coagulation profile: Essential before invasive procedures (liver biopsy). Vitamin K1 (1–5 mg SC/IM) should be administered if coagulopathy suspected.

1. Nutritional support (cornerstone of therapy):

• Feeding tube: esophagostomy (E-tube) or gastrostomy (PEG/G-tube) preferred
• Target: resting energy requirement (RER) = 70 x (body weight in kg)^0.75
• Start at 25–33% of RER, increase to full RER over 3–5 days
• High-protein, calorie-dense recovery diet (Hill's a/d, Royal Canin Recovery)
• Enteral feeding is superior to parenteral nutrition

2. Fluid therapy: Lactated Ringer's with potassium supplementation. Avoid dextrose-containing fluids (promotes hepatic lipid accumulation).

3. Anti-emetics: Maropitant (1 mg/kg SC q24h) or ondansetron (0.5–1 mg/kg IV/PO q12-24h).

4. Appetite stimulation: Mirtazapine or capromorelin — adjunct only, not replacement for feeding tube.

5. Vitamins and supplements: Vitamin K1, vitamin E, thiamine (50–100 mg IM/IV), taurine, carnitine.

6. Refeeding syndrome monitoring: Monitor phosphorus, potassium, magnesium. Supplement as needed.

7. Treat underlying cause: Pancreatitis, CKD, cholangiohepatitis, IBD.

Prognosis: 60–85% survival with aggressive nutritional support and feeding tube.