The liver is the largest gland in the body, and one of the most important for overall health. One of the liver's many functions include production of bile, a fluid substance involved in the digestion of fats. The gallbladder, situated in the concave of the liver, acts as a storage unit for bile, releasing the concentrated bile into the common bile duct as it is needed for fat digestion. The bile ducts begin within the liver itself as tiny channels to transport bile. The ducts join together to form larger bile ducts and finally enter the extrahepatic bile duct, or common bile duct, which empties into the upper small intestine. This system of bile ducts is known as the biliary tree.

Cirrhosis of the liver is generalized (diffuse) formation of scar tissue, associated with regenerative nodules, or masses, and deranged liver architecture. Fibrosis of the liver involves the formation of scar tissue that replaces normal liver tissue. This condition can be inherited or acquired. Doberman pinschers, cocker spaniels, and Labrador retrievers are susceptible to long-term (chronic) inflammation of the liver; a condition known as chronic hepatitis.

Symptoms and Types

• Seizures
• Blindness
• Fluid build-up in the abdomen
• Lack of energy
• Loss of appetite (anorexia)
• Poor body condition
• Vomiting
• Diarrhea
• Constipation
• Black, tarry stools due to the presence of digested blood
• Increased thirst
• Increased urination
• Yellowish discoloration of the gums and other tissues of the body
• Possible bleeding tendencies (uncommon)
• Skin lesions with superficial, ulcerative inflammation (superficial necrolytic dermatitis)

Causes

• Long-term (chronic) liver injury
• Long-term (chronic) inflammatory bowel disease (IBD)
• Drug- or toxin-induced liver injury - copper-storage liver disease (copper-storage hepatopathy); medications to control seizures (known as anticonvulsants); azole medications to treat fungal infections; medication to treat intestinal parasites (oxibendazole); antibiotic (trimethoprim-sulfamethoxazole); nonsteroidal anti-inflammatory drugs (NSAIDs); long-term (chronic) food-borne toxin (aflatoxins)
• Infectious disease
• Long-term (chronic) blockage of the extrahepatic or common bile duct (extrahepatic bile duct obstruction) - lasting more than six weeks

Diagnosis

Your veterinarian will perform a thorough physical exam on your dog, taking into account the background history of symptoms and possible incidents that might have precipitated this condition. A blood chemical profile, a complete blood count, an electrolyte panel and a urinalysis to rule out other causes of disease are also standard examination procedures.

A fine needle aspirate should be taken from the liver for a sample to be sent for cytologic analysis. A liver biopsy taken via laparoscope may also be necessary to form a definitive diagnosis.