Omega-3 Fatty Acids For cats

What are omega-3 fatty acids?

Omega 3 oils are a group of essential polyunsaturated fatty acids that are important for several functions in the body. There are eleven types of fatty acids, however, the two most important ones are eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) which are found primarily in marine sources including coldwater fatty fish such as salmon, tuna, phytoplankton, other marine plants and fish oil supplements. EPA and DHA are long chains of bonded carbon and hydrogen atoms with a carboxyl group on its end.

Because omega-3 fatty acids are nutrients that are used to manage disease, they are considered nutraceuticals. Mammals are unable to synthesise omega-3 fatty acids and must obtain them via food, which makes them essential.

What do omega-3 fatty acids do?

Omega-3 fatty acids play an important role in the body as components of the phospholipids that form the structures of cell membranes, provide energy for the body and are used to form eicosanoids. Eicosanoids are signalling molecules that function in physiological systems and pathological processes including inhibiting inflammation, allergy and fever responses, contributing to the perception of pain, controlling blood pressure and regulating cell growth.

  • Reduces inflammation: Omega-3 fatty acids are stored in the cell membranes, where they provide structure to the cell membrane and can inhibit inflammatory cytokine secretion leading to a reduction in inflammation. Inflammatory diseases that can benefit should from omega-3 fatty acids include skin allergies (atopic dermatitis), arthritis, chronic kidney disease, heart disease and inflammatory bowel disease. One retrospective study of cats with chronic renal failure found that cats fed a renal diet with the highest EPA had the longest survival.
  • Improved brain development: DHA is essential for brain and retina development in kittens, these organs grow rapidly during pregnancy and during kittenhood.
  • Slowed tumour growth: Studies have shown that diets supplemented with omega-3 fatty acids can slow the growth of certain cancers, increase the efficacy of chemotherapy and reduce their side effects.
  • Lower triglyceride levels: Diets rich in omega-3 fatty acids have been found to lower triglyceride levels in people.
  • Improved cognitive function: Omega-3 fatty acids are a major building block for the brain cells and have been shown to reduce the risk of Alzheimer’s disease, dementia, and other problems with cognitive function in people. Cognitive decline (feline dementia) can occur in senior cats, who may benefit from omega-3 fatty acids in their diet.
  • Reduces shedding: A 2018 study found fermented fish oil which contained both DHA and EPA helped stimulate follicle growth in rats which may help to reduce shedding.

Should I give my cat omega-3 fatty acids?

Most commercially prepared cat foods should contain omega-3 fatty acids which will be listed in the ingredients. If you are considering supplementing your cat’s diet with omega-3 fatty acids (or any other nutrients) to prevent or manage a disease, speak to your cat’s veterinarian for information on dosage, frequency and brand.


Omega-3 fatty acids are generally well-tolerated in cats, the most common side effects are gastrointestinal disturbances and greasy skin. GI symptoms can be reduced by feeding omega-3 fatty acid supplements with food.

Omega-3 fatty acids can disrupt the ability of the platelets to form blood clots and must be used with caution in cats with thrombocytopenia.

High amounts of cod liver oil can cause vitamin A and D toxicosis.


The recommended dose for fish oil is 40 mg/kg for EPA and 25 mg/kg for DHA. Once again, speak to your veterinarian before supplementing a cat’s diet. It is recommended pet owners purchase omega-3 fatty acids formulated for pets and not humans.

Some omega-3 fatty acid supplements use flaxseed oil, which is a rich source of alpha-linolenic acid (ALA), however, conversion of ALA to EPA is inefficient in cats due to the low activity of the enzyme delta-6 desaturase. Look for omega-3 fatty acids made from marine sources which contain EPA and DHA.


  • Julia Wilson, 'Cat World' Founder

    Julia Wilson is the founder of Cat-World, and has researched and written over 1,000 articles about cats. She is a cat expert with over 20 years of experience writing about a wide range of cat topics, with a special interest in cat health, welfare and preventative care. Julia lives in Sydney with her family, four cats and two dogs. Full author bio

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