The signs of liver disease in dogs are not always specific at first. Early symptoms include loss of appetite, weight loss, vomiting and diarrhea. Vomiting is the more common. Drinking excessive water and urinating frequently may be the first signs to manifest.
The dog's liver swells in the early stages of liver disease. Over time, cirrhosis sets in, causing the cells of the liver die while leaving scar tissue behind. The scar tissue causes the liver to become rubbery and firm. Although cirrhosis is not reversible, it is possible for a dog's liver heal itself to the point of normal liver function before the disease becomes terminal. Recovery depends on early detection and discovering the underlying cause of the liver disease.
Causes of Liver Disease in Dogs
Diseases, chemicals, drugs and toxins can cause liver disease in dogs. Infectious canine hepatitis, leptospirosis and heartworms directly affect the liver. Diseases such as Cushing's syndrome anddiabetes mellitus can lead to liver disease. Primary tumors and metastatic tumors are two main causes of liver failure in dogs.
Chemicals that cause liver damage include carbon tetrachloride, insecticides, phosphorus, selenium, arsenic, iron and toxic levels of lead. Medications given in excess or over a prolonged time period can cause liver disease. Drugs that may damage the liver are anesthetic gases, antibiotics, antifungals, dewormers, diuretics, analgesics anticonvulsants, testosterone preparations and corticosteroids.
Certain plants and herbs such as ragwort, blue-green algae, certain mushrooms and corn contaminated with the mold aflatoxin may cause liver failure in dogs.
A blocked bile duct is rare, but should be considered when a dog develops unexplained jaundice. Gallstones, liver flukes, tumors or pancreatitis can block bile ducts and cause liver disease.
Blood tests, ultrasound and CT scans all assist in diagnosis the cause of liver disease in dogs, but only biopsying the liver is definitive. Recovery depends on how long the dog has gone untreated and the cause and extent of liver disease. This will determine whether the disease can be treated surgically or controlled with medications.
When infectious diseases cause liver disease in dogs, it is best to treat the underlying condition. Liver problems caused by drugs or poisons usually have temporary effects that reverse themselves after the exposure ends. Bile duct obstructions and primary tumors may require surgery.
Controlling and preventing the complications of liver disease, particularly hepatic encephalopathy and bleeding, is imperative. This may demand a special low protein diet, decreasing levels of blood ammonia, avoiding situations that potentially cause seizures, monitoring blood-clotting factors, correcting electrolyte abnormalities and preventing stomach and duodenal ulcers. Natural supplements such as SAM-e and milk thistle are frequently used to repair and maintain liver function in dogs.