Euthanizing a Dog with Liver Failure: A Vet’s Perspective

First, remember that liver disease is not necessarily the same as liver failure. Liver failure is a unique, severe condition that is defined later in this article.

Deciding when to euthanize a dog with liver failure can be difficult. It’s important to consider that the prognosis for recovery from liver failure is less than 20%, even with excellent care. You may want to consider providing a peaceful death for your pet, rather than allowing them to suffer needlessly for several more days.

To determine whether your dog has a good quality of life, you can use a quality of life questionnaire. The HHHHHMM Quality of Life Scale is the one I recommend to my clients. It focuses on your pet’s ability to eat and drink, the effectiveness of pain management, and their level of participation in daily activities.

It’s important to answer the questions as objectively as possible. You may also want to seek the opinion of a trusted family member or friend. Take some time to weigh your options carefully before making a decision about euthanizing your pet.

Making the decision to say goodbye

Liver failure can affect dogs in different ways. Some may only have a poor appetite and vomiting, while others may be so sick that they are unable to move and are constantly panting in discomfort. It may seem clear that the latter case is a good candidate for euthanasia, but it can be challenging to make objective decisions when it’s your beloved pet.

Unfortunately, many pet owners admit that they waited too long to consider euthanasia once the situation is over. On the other hand, I’ve rarely heard someone say they euthanized their pet too soon.

The liver is a vital organ that performs numerous functions in the body. It’s exceptionally tough and can even regenerate itself if it has been damaged. Some of the critical roles of the liver include:

• Producing proteins that help in blood clotting
• Generating bile acids to assist in food digestion
• Creating new red blood cells
• Metabolizing fats, carbohydrates, and proteins
• Storing essential vitamins and minerals
• Eliminating toxins and drugs from the bloodstream
• Supporting the immune system.

What is liver failure in dogs?

Liver failure is a severe illness caused when over 75% of the organ is damaged.(2) There are two primary forms of liver failure: acute and chronic. In some cases, a dog with chronic liver disease may suddenly experience a significant worsening of their symptoms, known as “acute on chronic” liver failure.

Acute Liver Failure (ALF) is a sudden loss that can be caused by toxins, drug reactions, infectious diseases, and parasites. Interestingly, dogs with ALF may have a slightly better chance of recovering than those with a slower onset of the disease.

Chronic Liver Failure is a result of chronic liver disease that gradually progresses and leads to cirrhosis and eventual liver failure. Many dogs live with chronic liver disease, which can be caused by copper accumulation, infections, immune-mediated disease, and unknown causes.

How does the condition affect my dog’s body?

Liver failure affects multiple body systems, causing fluid buildup, slow blood clotting, infection susceptibility, scarring, and brain damage due to high ammonia levels. 

Is it painful for my dog?

Liver failure can cause pain in dogs, but they may not always show obvious signs of discomfort. It’s important to observe your dog closely and evaluate their behavior objectively. 

Compare their current behavior to how they acted when they were happy and healthy. Are they still eating with enthusiasm? Do they greet you when you come home? Can they still go outside to relieve themselves?

If you’re unsure about your dog’s condition, it’s best to involve your veterinarian. Even in cases where recovery isn’t possible, your vet can help make your dog as comfortable as possible during their remaining time. 

A 2016 study of 49 dogs with acute liver insufficiency found that the most common symptoms were loss of appetite, vomiting, neurological problems, excessive thirst, and increased urination.(5)

Some other common symptoms include:

Some dog breeds have more liver problems than others. Some have congenital problems like portosystemic shunts and others are suspected to lack normal liver de-toxifying processes. 

• American Cocker Spaniel
• Australian Cattle Dog
• Australian Shepherd
• Bedlington Terrier
• Bichon Frise
• Cairn Terrier
• Dalmatian
• Doberman Pinscher
• German Shepherd Dog
• Golden Retriever
• Havanese
• Irish Setter
• Irish Wolfhound
• Labrador Retriever
• Maltese Terrier
• Miniature and Toy poodles
• Miniature Schnauzer
• Old English Sheepdog
• Pekingese
• Pembroke and Cardigan Welsh Corgis
• Pomeranian
• Samoyed
• Scottish Terrier
• Shih Tzu
• West Highland White Terrier
• Yorkshire terrier

In one study, the most common causes of canine liver failure were cancer, presumed Leptospirosis and disruption of blood supply.(5) Additionally, more than 900 substances such as medications, toxins, and herbs have been identified as factors leading to ALF (3)

Drugs

Drugs are one of the most common causes of liver failure in dogs (2). Some drugs cause direct injury to hepatic cells, but some drugs cause an idiosyncratic (unexpected) adverse reaction. Idiosyncratic reactions usually happen when the liver processes the drug into a toxic substance. 

Drugs that are more likely to cause idiosyncratic toxic reactions are non-steroidal anti-inflammatory drugs, trimethoprim-sulfa, Lysodren, ketoconazole and azathioprine. 

There is no way to predict which dogs will have a problem and which ones won’t. The drug might be fine in most dogs but can cause a major problem in a few. 

Infectious Diseases

Infectious diseases can destroy liver cell function and tissue structure. Younger dogs and outdoor dogs have a higher risk of contracting the following infections: 

• Viral – Canine Adenovirus I (puppies)
• Bacterial – Leptospira, Salmonella, Rickettsial/tick-borne
• Fungal – Histoplasmosis, Blastomyces, Coccidioides
• Parasitic – Heartworms, protozoa

Congenital Disease 

Congenital disease means a problem present at birth that may not show up until later in life. These may be caused by abnormal circulation or abnormal cellular function. 

Portosystemic shunts (PSS) and portal vein hypoplasia are conditions in which blood doesn’t flow properly through the liver. Copper storage hepatopathy (CSH) occurs when too much copper is stored in the liver due to abnormal cellular elimination of the element.

Dogs often eat things they shouldn’t and the world is full of potential liver toxins. It could be a chewed plant from your yard or a fungus in their food. Sometimes we don’t even know where the toxin came from.

Some common toxins that can cause liver failure in dogs: 

Pancreatitis and Cancer

Pancreatitis is a common disease caused by inflammation of the pancreas. Dogs with severe pancreatitis can have leakage of pancreatic enzymes into the tissues of the abdomen. The resulting inflammation can lead to liver damage.

Primary liver cancer is rare in dogs, accounting for less than 1.5% of all cancers in dogs.(7) However, metastatic cancer of the liver, which is cancer that has spread to the liver from other sites in the body, is much more common. Senior dogs with cancers like hypodermal hemangiosarcoma are more likely to develop metastases in the liver.

The first goal is to identify the cause of liver disease and treat it appropriately. It’s not always possible to find the cause and not all underlying diseases have a specific treatment.

Supportive care is an important part of dog liver disease treatment. Anti-nausea medication, antibiotics and general liver support such as ursodeoxycholic acid and SAM-e are often used. Therapeutic diets can be helpful if your dog is still eating.

Dogs who are unable to eat or have extreme symptoms of liver failure require hospitalization. Treatments for severe cases include IV fluid therapy, therapeutic enemas and plasma transfusions.

Technically, it is possible to give a dog a liver transplant from a donor dog. The reason it’s not done routinely is partly that it’s cost-prohibitive. The other reason is that graft rejection is a very big problem that is hard to control in dogs.  

A related treatment that shows promise is stem cell therapy. A Chinese study published in 2019 showed that canine adipose-derived mesenchymal stem cells injected intravenously helped restore some level of liver function in dogs with experimentally-induced liver damage (10). 

This research is encouraging but stem cell therapy in dogs has a long way to go to prove it’s safe and effective. 

Dogs with chronic liver disease may survive months to years before they have liver failure.(11)

Liver failure in dogs can have a poor prognosis, with most dogs surviving only a few days to weeks. Dogs with significantly elevated bilirubin levels, blood clotting issues, or hepatic encephalopathy have the shortest survival times. 

Greater than 80% of dogs with acute liver failure die in spite of all treatments.(5) Those with chronic liver disease have a better chance of long-term survival depending on the cause and whether a specific treatment is available. 

Once a dog reaches end-stage liver disease, recovery is unlikely.

What should I feed my dog?

Therapeutic feeding of a dog with end-stage liver disease requires consulting with a veterinarian. 

In general, it is best to avoid foods high in protein. A compromised liver cannot process protein normally and nutritional protein contributes to high blood ammonia levels. 

Prescription diets like Hill’s l/d are formulated with limited digestible protein to minimize ammonia formation. Feeding your dog smaller meals 3-4 times a day may ease the strain on the liver.

Summary