Chronic hepatitis (CH) in dogs is definitively diagnosed by hepatic biopsy, which remains the gold standard, after ruling out infectious, toxic, copper-associated, and neoplastic causes through a structured pre-biopsy workup. Journal of Vete…+1
The minimum diagnostic database before biopsy includes serum alanine aminotransferase (ALT) activity, full biochemistry panel, urinalysis, abdominal imaging, and infectious disease screening. CH is defined by persistent ALT elevation greater than 2 times the upper limit of normal accompanied by histopathological changes: hepatocellular apoptosis or necrosis, a variable mononuclear or mixed inflammatory cell infiltrate, regeneration, and fibrosis. Journal of Vete…+2 Hepatitis of 4 to 6 months' duration meets the threshold for classification as chronic. Journal of the…
Infectious causes must be excluded before attributing CH to immune-mediated or idiopathic etiologies. Leptospira interrogans serovars Icterohaemorrhagiae and Pomona and chronic infections with L. interrogans serotype Grippotyphosa and L. kirschneri serotype Grippotyphosa are associated with hepatic disease in dogs, presenting with vacillating to markedly increased liver enzyme activity with or without hyperbilirubinemia. MSD Vet Manuals Antinuclear antibody testing, endemic infectious disease titers or antigen tests, and a thorough drug, toxin, dietary, environmental, and family history are required before a case can be classified as idiopathic. MSD Vet Manuals
Copper-associated hepatitis is the most important specific etiology to exclude and requires both quantitative hepatic copper determination and qualitative copper staining on biopsy. Labrador Retrievers are predisposed to copper-associated hepatitis through mutations in the copper transporter genes ATP7B and ATP7A, and dietary copper intake contributes to disease progression in this breed. Journal of Vete… Lobe-to-lobe heterogeneity in hepatic copper deposition and loss of detectable lobular copper distribution in late-stage disease can complicate exclusion of copper toxicosis even with biopsy. Journal of Vete… Failure to respond to penicillamine chelation is an additional indicator that copper is not the primary driver. Journal of Vete…
Idiopathic CH is a diagnosis of exclusion, defined as chronic necroinflammatory self-perpetuating liver disease with a nonsuppurative inflammatory infiltrate after rigorous pursuit of an underlying cause. MSD Vet Manuals Autoimmune hepatitis falls within this classification. MSD Vet Manuals In one report, 64% of CH cases were classified as idiopathic after exclusion of other causes. Journal of Vete… Immune-mediated CH is specifically characterized histopathologically by interface hepatitis, and its diagnosis additionally requires exclusion of copper, medications and toxins, infection, and neoplasia. Veterinary Clin…
Lobular dissecting hepatitis (LDH) is a distinct idiopathic subtype that most often affects juvenile dogs and carries a worse prognosis than other forms of CH. Age at clinical presentation ranges from 3 months to 7.2 years. Journal of the… Affected dogs typically present with ascites, jaundice, or both, and clinical signs include abdominal distension, weight loss, gastrointestinal signs, polyuria, and polydipsia. Journal of the… Dogs with LDH have significantly shorter survival times compared to dogs with other types of CH, and once cirrhosis is present, long-term survival is poor. Journal of the…
Histopathology should be interpreted using World Small Animal Veterinary Association (WSAVA) Liver Standardization Group criteria, which score necroinflammatory activity (grade) and fibrosis (stage). Veterinary Clin…+1 Interobserver agreement for fibrosis and necroinflammatory activity scoring is reported as fair to poor, and ideally samples should be reviewed by a pathologist with hepatic histopathology expertise. Journal of Vete…+1 Biopsy method affects sample quality and diagnostic yield. Journal of Vete…
Negative prognostic indicators on clinicopathologic assessment include hyperbilirubinemia, hypoalbuminemia, hypoglycemia, and the presence of ascites or cirrhosis, though these typically appear only in advanced or end-stage disease. Journal of Vete… The severity of histological changes can correlate poorly with clinical signs — dogs with severe clinical signs may have disproportionately minor histological changes and vice versa. Journal of Vete… Median survival time after diagnosis averages approximately 1.5 years. Journal of Vete…
Serum metabolomics and plasma amino acid profiling are emerging noninvasive approaches but are not yet validated for routine clinical use. The serum metabolome differs among healthy dogs, dogs with congenital portosystemic shunts, and dogs with CH, with increased aromatic amino acids and xylitol characterizing portosystemic shunt cases. Journal of Vete… Plasma hypoaminoacidemia does not occur in dogs with non-hepatocutaneous syndrome chronic liver disease, including CH — marked depletions below 30% of the normal reference range in arginine, citrulline, glutamine, glycine, and proline are characteristic of hepatocutaneous syndrome specifically and can help differentiate it from CH. Journal of Vete…
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