Skip to main content

Carnivores & Liver Disease


Dr. Corinne Chapman

The liver is the largest gland in the body of our pet dogs and cats. As carnivores, a large liver is required to manage and metabolize their high intake of concentrated proteins and fats.

It is one of the most important organs of the body, acting as the main filtering and clearing agent. The liver is responsible for the manufacture of vital blood proteins, fats, and blood clotting factors; the formation and storage of energy (glycogen) for the production of blood sugar as needed by the body; the storage of fat-soluble vitamins and iron; the detoxification of drugs, chemicals, and other unusable substances; the inactivation of hormones no longer needed, and the secretion of bile and other factors necessary for proper digestion. All venous blood supply travels through the liver to be filtered, detoxified, and prepared for elimination through the kidneys. So a "sick" liver is a serious problem!

Many scientists have theorized over the causes of liver disease. The most up-to-date theories focus on genetics, drug-induced trauma, poisons, malnutrition, parasites, environmental stresses, cancer, and infectious diseases (bacterial, viral, fungal), just to name a few. I would like to add their present day diet to the list.

Until recently, traditional medical therapy for patients with liver disease included dietary protein restriction, or "low protein" diets. Today, this topic is controversial, in both human and animal patients with liver disease. It has been shown that people with some forms of liver disease actually require increased dietary protein. Feeding a human patient a low protein diet may actually contribute to further liver degeneration and, possibly, hepatic encephalopathy (HE). Hepatic encephalopathy is a metabolic disorder affecting the Central Nervous System that develops as a result of liver disease. HE develops with the accumulation of ammonia in the blood stream due to prolonged circulation of toxins in the blood when the liver is overwhelmed. Unfortunately, this can lead to seizures, coma, and sometimes death.

When diagnosed early, treatment of liver disease can be very rewarding. Diagnosis includes blood tests that look at liver-specific proteins like enzymes (ALT, ALKP), bilirubin, cholesterol, albumin, and bile acids. Abdominal x-rays, ultrasound, and liver biopsies are also invaluable aids in the determination of the type of liver disease. Several forms of liver disease exist in our pets, such as Chronic Active Hepatitis and cirrhosis, Portosystemic Vascular liver shunts, Cholangiohepatitis, Copper Storage disease, and Feline Hepatic Lipidosis or "fatty liver".

Dietary management is the main area to focus on when the liver is failing. The goal is to provide all the necessary nutrients that may be lost due to the failure of liver processing, without overtaxing the liver. The liver patient requires high levels of top quality protein to provide the essential amino acids in an easily digestible carrier, which will not produce high levels of ammonia during digestion. Remember, we want to stay away from toxic ammonia levels or the patient may develop HE. So, it is important to find that balance.

Each patient is unique. You need to feed adequate levels of high-quality proteins and find the "toleration" level for that patient. Our feline friends, being obligate carnivores, with very little use for plant proteins, must be monitored religiously. Dogs, however, can afford a little plant protein to dilute the rich meat protein levels, especially red meats. The red meats, like beef, tend to produce high levels of ammonia. High quality, but low-intensity proteins such as cottage cheese, eggs, fish, or chicken, are all recommended for the liver "dis-eased" patient. And, if the protein quality and level is too low, your pet will begin to break down their own body tissues (ie. muscle atrophy or breakdown of the skeletal system, the cardiac muscle of the heart, and the smooth muscle of the bowels). Not good.

Caution should be used as well when considering carbohydrates. High-quality carbohydrates like crushed fruits and vegetables are helpful in driving the metabolism of the body. Fibre, at least temporarily, may help in the beginning, to take up excess ammonia, preventing HE. Essential fatty acids, like a cold water fish oil, act as added protection for the cells of the liver. Vitamin and mineral supplementation are also important with the liver unable to keep up with this vital job.

In other words, the diet for dogs and cats with liver disease should be maximally digestible, be completely absorbed within the small intestine, and provide restricted amounts of protein of high biological value (high quality). These guidelines will allow for maximal protein absorption, adequate regeneration of liver tissue, and restrict the possibility of HE. Feeding the patient frequent, small meals will also help to reduce the liver's workload. An early diagnosis and proper feeding can regenerate liver tissue and reverse liver disease.

I am already concerned enough about the feeding of inferior protein to healthy animals ad infinitum. This alone burdens the kidneys and liver, leaving the system toxic and disease prone. In my opinion, dry kibble, the artificial pet diet of today, is dehydrating our pets. By having them eat a dehydrated food every day, we are contributing to their early demise. Why would we expect our beloved friends to tolerate these ingredients forever without side effects down the line? Incidentally, dry kibble is much the same as Kraft Dinner without the milk or butter. Mmmm ... imagine eating that day-in-and-day-out?

Our patient needs to reduce the level of protein, not the quality. And only initially. Changing to a more natural diet, like a raw or homemade diet, is my recommendation. This is best done under the supervision of your veterinarian who can develop a proper menu plan and continue to monitor the liver disease via regular blood testing. To switch to a dry kibble formula to treat liver disease is to continue to contribute to the disease itself. Not only are most dry kibble diets of poor quality, but they also contribute to further dehydration and the high carbohydrate loads of poor quality make the liver work too hard. Take, for example, the Hills Canine l/d ("liver" diet) ingredient list: Brewers rice, pork fat (preserved with mixed tocopherols and citric acid), dried egg product, soybean meal, pasta product, soy fiber, flaxseed, pork protein isolate, chicken liver flavor, vegetable oil, powdered cellulose, etc & where's the real food?

I believe that these artificial diets are contributing to many diseases in our pets, including liver disease. It is unfortunate that we, the public, believe processed food is safe and reliable. We want our food, and that of our pets, to be simple-to-serve, complete, and balanced. No one really eats like this. Not even us! We balance our meals over several days, not hours. By feeding our young pets a diet of fresh and raw ingredients, we can help to prevent the disease from ever beginning. Start providing your young pets with the freshest foods you can and I believe they will live a long, healthy life.