Nutritional Supplements for Cats with Liver Disease

Jennifer Coates, DVM
By Jennifer Coates, DVM on Apr. 18, 2014

In the last Nutrition Nuggets for Cats, we talked about Feeding Cats with Liver Disease. Today, let’s touch on the use of nutritional supplements (nutraceuticals) to help manage liver disease. 

The North American Veterinary Nutraceutical Council defines a nutraceutical as “a non-drug substance that is produced in a purified or extracted form and administered orally to patients to provide agents required for normal body structure and function and administered with the intent of improving the health and well being of animals.” 

Nutraceuticals used in liver disease generally fall under the categories of vitamins and antioxidants.


Vitamins for Liver Disease

The liver is the major storage area for vitamins and converts provitamins into their active form.  Both fat-soluble vitamins (A, D, E and K) and water-soluble vitamins (C and B complex) can become deficient as a result of some liver diseases due to:

  • Impaired bile flow (bile helps transport fat-soluble vitamins)
  • An increase in demand
  • Reduced storage capacity 

Vitamin E has many beneficial effects in the body, including removing “free radicals” that form during normal chemical processes. Free radicals can cause damage to cells and DNA. Vitamin E also reduces the fibrosis (scarring) that occurs in some liver diseases. 

Vitamin K deficiency can cause serious blood clotting abnormalities and increased risk of bleeding. Supplementation is recommended with some liver diseases and may be necessary prior to invasive procedures such as liver biopsy or feeding tube placement.

Deficiencies of several of the B vitamins (B6, B12, and B1) may worsen some liver diseases. Cats are particularly prone to vitamin B12 (cobalamin) deficiency. Cobalamin levels should be measured or supplemented routinely in cats with liver disease.


Antioxidants for Liver Disease

Antioxidants made in the body help repair and maintain liver cells. Adding additional nutraceuticals for their antioxidant effects can improve the overall health and survival of cats with liver disease.

N-acetylcysteine (NAC) — a derivative of the amino acid cysteine

  1. Used primarily in acetaminophen (Tylenol) toxicities or other diseases causing oxidative stress
  2. Usually administered intravenously at the onset of liver disease when cats are too ill to take oral medications. The patient is then switched to s-adenosylmethionine (SAMe) with broader metabolic benefits and easier oral administration.

S-adenosylmethionine (SAMe) — a modified amino acid

  1. A cytoprotectant that protects cells from damage
  2. Helps cell regeneration
  3. Improves the flow of bile

In cats, SAMe is useful for hepatic lipidosis (i.e., fatty liver disease), chronic hepatitis, and several other liver diseases. 

Silymarin — an extract from the milk thistle plant

  1. Protects liver cells from damage through its antioxidant, anti-inflammatory, and immune-modulating effects
  2. Effective for mushroom poisoning in dogs, Hepatitis C virus in people, and many liver diseases in cats

When choosing a nutraceutical, it is important to consider product quality, safety, and efficacy. Reputable manufacturers make products that meet their label claims for active ingredients, efficacy, and purity. Used in combination with diets for liver disease, nutraceuticals can help improve the length and quality of cats’ lives.

Dr. Jennifer Coates


Twedt, D.C. (2010). Treatment of Liver Disease: Medical and Nutritional Management. Presented at the Western Veterinary Conference, Las Vegas, N.V.

Center, S.A. (2011). Use of Nutraceuticals in the Management of Hepatic Health. Presented at the Western Veterinary Conference. Las Vegas, N.V.

Image: Anthony Bolan / Shutterstock

Jennifer Coates, DVM


Jennifer Coates, DVM


Dr. Jennifer Coates is an accomplished veterinarian, writer, editor, and consultant with years of experience in the fields of veterinary...

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