Liver Disease in Dogs

Overview:

Liver disease is a term used to describe a disease or disorder affecting the liver. It may be acute or chronic.

The liver is the largest internal organ of the body.  It is located in the abdomen, under the diaphragm. It performs many functions which are essential to life.

• Cleans the blood by removing medications & toxins

• Regulating chemicals in the blood

• Produces & secretes bile, which aids digestion & absorption of fats. Bile is a greenish-yellow fluid which consists of bile acids & waste products  such as bilirubin. It is made by the liver & stored in the gall bladder.

• Produces specific enzymes which aid digestion of food

• Converts most sugars into glycerine which it stores up as glycogen until required

• Fat soluble vitamins A, D, E and K need bile in order to be absorbed by the body

• Production of blood clotting factors

• Manufacture of certain hormones

• Breaks down hemoglobin creating metabolites that are added to bile as pigment.

• The liver changes ammonia, a toxic by product of protein metabolism into urea, which is excreted in the urine.

Liver Disease:

There are several causes of liver disease in dogs, which include:

• Bacterial, viral or parasitic infection such as canine hepatitis, leptospirosis, chronic ear infections, heartworms.

• Damage caused by exposure to  drugs, chemicals & toxins (Toxic Hepatopathy).

• Cancer: There are many different types of tumour which affect the liver. Primary liver cancer (liver beginning in the liver) is uncommon in dogs. Most cancers of the liver originate from some other site & spread to the liver.

• Liver shunt: Liver shunts are abnormal communications between the portal & systemic venous system which allows intestinal blood to be delivered to the systemic circulation prior to hepatic detoxification. A shunt means that blood bypasses the liver, resulting in blood not being detoxified by the liver & a rise in toxins. Liver shunts may be congenital or acquired.

• Trauma such as a car accident.

• Heatstroke.

The liver is able to function until 80% of liver cells have died. Therefore, if you notice any symptoms described below, seek veterinary attention immediately.

What are the signs of liver disease in dogs?

Symptoms may vary depending on what has caused liver disease, but common symptoms include:

• A common sign of liver disease is icterus (also known as jaundice). Signs of icterus are yellowing of the eyes, skin & mucous membranes.

• Loss of appetite.

• Abdominal effusion.

• Weight loss.

• Polyuria (increased urination).

• Polydipsia (increased water consumption).

• Enlargement of the liver.

• Lethargy.

• Diarrhoea.

• Vomiting.

• Seizures.

• Bad breath.

How is liver disease diagnosed?

Your veterinarian will perform a physical examination of your cat & will want to run several tests, including a biochemical profile to look at;

• ALT (alanine aminotransferase) is an enzyme produced in the liver cells.  The ALT test determines the level of this enzyme in the blood, which increases when damage to the liver cells has occurred.  

• AST (aspartate aminotransferase) is an enzyme also found in skeletal & cardiac muscle cells, the brain & red blood cells. Elevated AST in the blood is also an indicator of liver disease, although as it is found in other organs, it is not as specific for liver cell injury as elevations in ALT.  

• Bilirubin: This is a major breakdown product of red blood cells. When red blood cells wear out they are trapped in the spleen and destroyed, releasing bilirubin into the blood. This type of bilirubin is called unconjugated. This bilirubin is transported in the blood to the liver, where it is taken up & conjugated (joined with glycuronic acid). This conjugated form may either be stored in the liver cells or excreted into the bile.  Bilirubin levels are increased in cats with liver disease, gallbladder disease or have excessive destruction of  red blood cells (known as hemolysis).

• Low blood urea nitrogen.

• Low blood glucose.

• Low potassium (hypokalemia).

• Low cholesterol.

• Albumin: This is a major protein of the blood plasma. It is manufactured by the liver. Low levels of albumin in the blood can be a sign of liver disease.

• Complete blood count

• Urinalysis

• Thyroid testing

• Bile acids tolerance test

• Ultrasound: An ultrasound can give your veterinarian an idea of the size & shape of your cat's liver & gallbladder, and detect gallstones & biliary obstruction (blockage of the flow of bile from the liver).

• X-Ray:  An x-ray may be taken to give your veterinarian an idea of the size & shape of your cat's liver. X-ray may also detect the presence of tumours.

• Biopsy: A liver biopsy is taken to determine the exact type of liver disease. This may be done at the same time as the ultrasound.

• Serologic Testing: Testing for diseases such as FeLV, FIV, FIP & toxoplasmosis may be taken as these diseases are associated with some liver disorders in cats.

How is liver disease treated?

Treatment depends on the cause of liver disease. But may include;

Damage by toxins:

• Supportive care such as intravenous fluids.

Liver Shunt:

• Surgical ligation.

• A prescription diet which is restricted in protein may be recommended.

• Supportive care, where necessary.

Cancers & tumours:

• Surgical removal of the tumours.

Infectious diseases:

• Medications such as antibiotics to treat the infection.

Heatstroke:

• Your veterinarian will carefully bring your cat's body temperature down to a safe level. 

• The cat may be given oxygen.

• Fluid therapy to correct dehydration. 

Your veterinarian may recommend a specific diet to assist in liver recovery.

Please note:

The medical articles on this site have not been written by a veterinarian & should not be considered a replacement for a veterinarian visit. The articles are provided for informative purposes only.

Always seek immediate veterinary advice for any problems (health or behavioral) in your pets. 

While great care has been made in the creation of these articles, we cannot guarantee the accuracy or omissions on these pages. If in any doubt whatsoever, seek professional medical advice.