chronic hepatits

Introduction: Chronic Hepatitis is actually a very generic term for several disease processes that occur most commonly in the dog. These diseases are both inflammatory and necrotizing, and the most significant inflammatory infiltrate are lymphocytes and plasma cells. This disease process has formally been called by several other names (Chronic Active Hepatitis, Chronic Lobular Hepatitis, Chronic Progressive Hepatitis) based upon human diseases and characteristic histologic lesions. Because Canine Chronic Hepatitis has many different etiologies, the term Chronic Hepatitis now describes all of the diseases producing the same general lesion. In cases that cannot be explained definitively by a single etiology, the term Idiopathic Chronic Hepatitis is used. In dogs there is a definite familial predisposition among some breeds, highly suggestive of a genetic component.

Chronic hepatitis commonly results in cirrhosis.
http://tpis.upmc.edu/tpis/HB/H00030m.html

Pathophysiology: The mechanisms of chronic hepatitis are poorly understood. There is evidence of immune mediated mechanisms as some dogs will respond positively to corticosteroids. Whether the autoimmune event occurs secondarily, or as a primary mechanism disease, is unclear. Copper accumulation is one of the few well documented causes of chronic hepatitis in dogs. Accumulation may be a consequence of disease as well as a contributing factor. However, hepatic damage is not consistent until copper levels exceed 2000 ug/g. Bedlington terriers may develop chronic hepatitis secondary to a congenital metabolic defect in biliary copper excretion (copper toxicosis). Chronic hepatitis can progress to cirrhosis which can, in turn, cause portal hypertension and the development of acquired portosystemic shunts.

Gross Pathology: The gross appearance of the liver will vary depending on the extent of the disease. As the disease progresses, there will be fibrosis and variable-sized regenerative nodules throughout the liver. The liver is generally reduced in size.

Cirrhosis-macrondularA.jpg (40692 bytes)

End Stage:
Chronic Canine Hepatitis

This is the final stage (Cirrhosis) in a case of chronic hepatitis in a Doberman Pinscher. This breed has a predilection for chronic hepatitis, especially females. Cirrhosis is a common outcome.

Medline Search: doberman and hepatitis

Histopathology: Chronic hepatitis is characterized by moderate to severe inflammation, piecemeal necrosis (hepatocellular necrosis of the cells adjacent to the portal tracts), bridging necrosis (necrosis and non-suppurative inflammation crossing the hepatic lobule), and neutrophils, though rare, may be present and suggest a bacterial component.

Species affected: Although most common in the dog, the cat may also experience chronic hepatitis. In dogs, the disease occurs with equal frequency in both males and females between the ages of 5 and 7 years.

Clinical signs: Often the presenting signs are vague and include vomiting, depression, lethargy, and anorexia. Weight loss may be accompanied by PU/PD. Increased severity of disease will lead to more typical signs of hepatic disease including ascites, icterus, and hepatic encephalopathy. Melena may occur due to gastroduodenal ulceration. Microhepatica, poor body condition, hypoalbuminemia, and histologic evidence of fibrosis all suggest chronic disease processes.