The liver performs over 500 essential functions — metabolism, detoxification, protein synthesis, bile production, and more. Liver disease in dogs encompasses a wide spectrum from mild, reversible hepatitis to severe, progressive cirrhosis. Early recognition and appropriate management significantly improves welfare outcomes.
Common Liver Diseases in Dogs
- Vacuolar hepatopathy: Steroid-induced or idiopathic glycogen accumulation; common, usually benign; elevated ALP is the hallmark. Management focuses on reducing steroid exposure if iatrogenic
- Acute hepatitis: Toxic (e.g., xylitol, aflatoxins, drugs), infectious (Leptospira, adenovirus CAV-1, Neospora), or immune-mediated causes; clinical signs from vomiting and lethargy to fulminant hepatic failure
- Chronic hepatitis: Breed-associated (Dobermann, Cocker Spaniel, Labrador) or copper-associated; progressive fibrosis leading to cirrhosis. Biopsy required for definitive diagnosis
- Portosystemic shunts: Congenital (single extrahepatic most common) or acquired (multiple); neurological signs from hepatic encephalopathy; surgical ligation often curative for congenital shunts
- Hepatic neoplasia: Hepatocellular carcinoma, lymphoma, metastatic disease
Clinical Signs
- Vomiting, diarrhoea, inappetence
- Jaundice (icteric mucous membranes and sclera)
- Polyuria/polydipsia
- Ascites (abdominal fluid accumulation) from hypoalbuminaemia
- Hepatic encephalopathy — neurological signs including disorientation, circling, seizures (particularly portosystemic shunts)
- Bleeding tendencies from coagulation factor deficiency
Diagnosis
Serum chemistry (ALT, ALP, GGT, bilirubin, albumin, total protein), bile acids stimulation test (pre- and post-prandial), coagulation profile, and abdominal ultrasound provide primary assessment. Liver biopsy (tru-cut or laparoscopic) provides definitive diagnosis for chronic hepatitis and guides treatment.
Treatment Principles
- Remove the cause where identifiable (discontinue hepatotoxic drugs, treat infection)
- Ursodeoxycholic acid — hepatoprotective, anti-inflammatory, and choleretic; used in chronic hepatitis
- S-adenosylmethionine (SAMe) — supports glutathione synthesis and hepatocyte function
- Milk thistle (silymarin) — antioxidant hepatoprotective supplement
- Low-copper diet and chelation therapy for copper-associated hepatitis
- Dietary modification — moderate, high-quality protein; avoiding high-fat, high-copper diets
- Management of complications — lactulose and dietary protein modification for encephalopathy; spironolactone/furosemide for ascites