Liver Failure in Dogs

Liver failure is also known as hepatic insufficiency, hepatic being an adjective applied to anything related to this organ. There are various reasons why a liver may fail, but the first thing we need to recognize is one of its most unfortunate aspects. Liver disease, i.e. any disease which negatively affects the liver, often begins asymptomatically. This means the disease is present, but the outward signs are not evident when looking at the dog's physical appearance and behavior. Inside, the liver disease may be destroying the liver and posing a serious threat to the dog's health.

The root cause of liver disease leading to liver failure is often due to an infection, genetic predisposition or lifestyle issues. However, trauma can also be at fault. Failure of the liver will usually occur in one of two ways:

• Acute liver failure: this is when the liver failure is sudden or rapid, often due to an infection or disease which works quickly to cause liver damage. The progress may have varying factors however, such as the metastasis of liver cancers. Some diseases may act in a similar way, but progress at different speeds.
• Chronic liver failure: this is when the progression is slower. Long term damage slowly lessens the functionality of the disease, providing various symptoms at different stages. The general term for long term chronic liver damage is cirrhosis.

As dogs cannot communicate their feelings verbally, we need to keep a keen eye on any changes in our dog's well-being. Unfortunately, with liver failure, the prognosis does not always look good once symptoms do begin to appear. In a 1995 study of chronic hepatitis and chronic cirrhosis in dogs, 94% with chronic cirrhosis died within a week of diagnosis^[2]. Those with chronic hepatitis, however, did manage to live up to 4 years after diagnosis.

If we can say that there are two main types of liver failure in dogs, its cause can be incredibly varied. Many diseases may degenerate the liver to the point of partial or total failure. Some cause of liver disease may be due to:

• Genetic factors: these may be due to conditions passed on from the parents.
• Poisoning: if the dog ingests something toxic, these toxins can overwhelm the liver and cause it to shut down.
• Lifestyle: if the dog does not live a healthy life, many factors will deteriorate their well-being with liver failure being one of them.
• Infections: when infections get severe and the immune system cannot defend against it, the toxins can detrimentally affect the liver.
• Trauma: road accidents, falls or similar accidents can result in trauma occurring and the shut down of liver function.

Types of liver disease in dogs may stem from one or a combination of these causes. They include:

• Infectious canine hepatitis: the most well-known form of hepatitis in dogs is infectious canine hepatitis. The dog contracts the virus from various secretions of other infected dogs such as blood, feces or mucus. Symptoms start to appear after the incubation period which is usually between 4 and 7 days. Fortunately, dogs can make a recovery, but damage to the liver may mean it will never fully repair.
• Hepatitis C: canine hepatitis C virus (CHV) is a relatively new discovery, so information is limited. We do know it deteriorates the liver and may even have been the originator of the human form of this virus according to a study in The Proceedings of the National Academy of Sciences^[3].
• Obesity: the accumulation of fat due to canine obesity can result in liver failure. It can affect the hepatic vein and destroy valuable enzymes^[4]. This is a chronic condition which worsens over time.
• Diabetes mellitus: a lack of insulin due to diabetes results in cells being unable to get nutrients. This leads to the cells in the liver breaking down and being unable to function, resulting in liver failure.
• Portosystemic shunts: a shunt is a vein which bypasses bloodflow incorrectly. A hepatic shunt is when the hepatic portal vein in the liver goes directly into the blood system without going into the liver at all. This means the blood is not detoxified and can be fatal. In dogs it is most commonly a hereditary genetic trait and affects smaller dogs such as the Yorkshire Terrier or Shih Tzu.
• Leptospirosis: a bacterial infection which affects the liver and kidneys. Is often caused by a wound being infected with the Leptospira bacteria or by cutting the mucus membrane in their mouths.
• Tumors: tumors can appear on the liver, both benign and malignant. If the tumor is caused by a cancer like hemangiosarcoma, the action is rapid and symptoms may only appear all of a sudden. Some skin tumors may not initially affect the liver, but eventually metastasize and cause hepatic insufficiency.
• Bile duct blockage: if there is a blockage in the bile duct, bilirubin does not travel to the intestine as it should and accumulates in the blood.
• Cirrhosis: this is a general term for liver failure, but is often accompanied by inflammation and can lead to liver cancer.
• Acetaminophen poisoning: a drug found in human medications such as paracetamol based analgesics or Tylenol which is poisonous to dogs even in low dosages.

Some breeds may have specific liver function problems which affect them more than others. One common problem in Shar Pei dogs is a disease known as Shar Pei fever. This condition leads to swelling and fever symptoms. Proteins can then build up in the liver and kidneys resulting in their failure.

Different causes of liver disease usually result in very similar symptoms of liver failure in dogs. This is because the essential outcome is the same; the liver is unable to fulfil its different functions. The results may manifest themselves in signs such as:

• Jaundice: when the liver does not function properly, bile accumulates in the body. This results in a yellowish tone being present in the skin. As most dogs are covered in fur, this is harder to see. However, it will present in the mucus membranes in the mouth and even in the eyes. Additionally, the dog's urine will become a dark brown color.
• Hepatic encephalopathy: toxins such as ammonia which cannot be broken down in the liver go into the blood and eventually affect the brain. This results in neurological abnormalities, so the dog may grow uncoordinated, disorientated and weak. Behavioral changes may occur and they may become soporific or even aggressive. In advanced cases seizures can present.
• Ascites: this is the accumulation of fluid in the abdomen. Liver disease lowers serum proteins and increases tension in the veins.
• Hemorrhaging: this usually occurs in more advanced cases. Bleeding can happen in the stomach, intestine or urinary system. Blood may then appear in their stool, urine or vomit. If we see this symptom of liver failure, then immediate action needs to be taken.
• Edema: another type of fluid accumulation, this time it affects the tissues themselves. They are also related to decreases in serum protein levels and can affect the extremities. This means if you see lumps form on their legs or paws, it could be a result of liver problems.

Gastrointestinal signs may also present if liver failure is present in dogs. They may include:

• Vomiting
• Diarrhea
• Weightloss
• Dehydration
• Different color stool
• Lack of appetite
• Bloating
• Pain

However, these above signs are shared by many gastrointestinal conditions. If the liver is affected, they will usually be in conjunction with more specific problems. This is why a veterinary examination is so important.

If you take your dog to the vet after observing these different symptoms of liver failure in dogs, they will need to run the appropriate diagnostic tests such as:

• Physical examination for signs of bloat or hardness
• Abdominal ultrasounds
• X-Rays
• Urinalysis
• Complete blood count (CBC)
• Biopsy

Treatment of liver failure in dogs will depend on the initial cause. Once diagnosis is achieved, then they will decide on the correct course of treatment. If the problem is due to blocked veins or a shunt, then surgery will likely be needed to repair the bypass or clear blockages. This will also happen if there is a blockage in the bile duct.

Surgery may also be an appropriate intervention if a tumor or cancer is present. In this case, the overall intervention may also include other cancer treatments such as chemotherapy. The extent of the cancer will also need to be determined. If the initial cause is an infection, then antibiotics and other treatments will likely be administered. Recovery and prognosis will depend on the amount of damage done to the liver. If the extent of the damage is too grave, it will mean end stage liver failure. End stage liver failure requires palliative care and the vet may even recommend they euthanize the dog.

As liver failure in dogs has many different causes, many of them cannot be actively avoided. However, since lifestyle is a big factor, there is a lot we can do to best prevent it. Prevention includes:

• Stop them from eating things they shouldn't and discourage this behavior with positive reinforcement.
• Be careful when walking in areas where there is a high risk factor of disease transmission.
• Take regular walks to prevent obesity and encourage overall well-being.
• Feed with quality dog food and ensure they are not overfed with treats.
• Vaccinate to inoculate against certain diseases such as leptospirosis.
• Deworm to avoid parasitical infestation.

This article is purely informative. AnimalWised does not have the authority to prescribe any veterinary treatment or create a diagnosis. We invite you to take your pet to the veterinarian if they are suffering from any condition or pain.

If you want to read similar articles to Liver Failure in Dogs, we recommend you visit our Other health problems category.