Chronic hepatitis in the dog--a review

Area of Science:

• Veterinary Pathology
• Hepatology
• Canine Internal Medicine

Background:

• Chronic hepatitis is a diverse inflammatory liver disease with controversial classification in both human and veterinary medicine.
• The etiology of chronic hepatitis in dogs remains poorly understood, unlike in humans where viral causes are increasingly identified.
• Current classification relies on morphology, but an etiology-based system is needed for better understanding and comparison between human and canine cases.

Purpose of the Study:

• To propose a new classification system for chronic hepatitis in dogs.
• To differentiate canine chronic hepatitis from the human disorder.
• To establish diagnostic criteria based on etiology and histopathology.

Main Methods:

• Review of existing literature on chronic hepatitis classification in humans and dogs.
• Histopathological evaluation of liver biopsies to assess necrosis, inflammation, and fibrosis.
• Development of a classification framework prioritizing etiological factors.

Main Results:

• A proposed classification system for canine chronic hepatitis based on etiology (infectious, drug-induced, autoimmune, idiopathic).
• Histopathological criteria include severity of necro-inflammatory activity (minimal to severe) and extent of fibrosis (none to cirrhosis).
• This etiological approach aims to resolve morphological classification controversies.

Conclusions:

• An etiology-based classification is essential for understanding and managing canine chronic hepatitis.
• Histopathological assessment of severity and chronicity complements etiological diagnosis.
• This framework facilitates comparison between human and canine chronic hepatitis.