Scarring and Abnormal Function of the Liver in Dogs

Cirrhosis and Fibrosis of the Liver

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.

Treatment

Patients with minimal signs can be treated on an outpatient basis as long as they are still eating normally. Patients with more severe signs should be hospitalized, given fluid therapy if necessary and have a feeding tube inserted if they are showing symptoms of anorexia. Electrolytes may be supplemented while administering fluids, and some patients respond well to B-complex vitamins. If there is abdominal fluid build-up, the fluid will need to be tapped and removed, and sodium restricted in the diet until the cause of the build-up has been resolved. Dogs displaying signs of hepatic encephalopathy (ammonia buildup in the blood causing neurologic signs) should have food withheld, as should dogs that are vomiting and/or suffering from inflammation of the pancreas. For hepatic encephalopathy, dogs may be given soy or dairy protein in combination with medical treatment to increase nitrogen tolerance. Such patients should have individualized protein portions suited to their level of hepatic dysfunction. Albumin levels should be maintained. If surgery is being considered in such patients, a clotting profile will be performed, sine patients with longer clotting times will have an increased chance of bleeding, even during minor surgeries.

Living and Management

Your veterinarian will schedule regular check-ups with you for your dog. At these visits, blood work will be done, including monitoring of total serum bile acids. Your veterinarian will also observe your dog's ongoing body condition and observe to see if fluid is building up in the abdomen. Contact your veterinarian if your dog's abdomen appears to be larger than normal, is behaving strangely, or seems to be losing weight.