by Dr Jeanette (Jeannie) Thomason

Essential fatty acids for dogs (Omega 3s).

EPA, (eicosapentaenoic acid) and DHA (docosahexaenoic acid) are considered essential Fatty Acids because they cannot be made in the body. In order to maintain optimal health and wellness, these fatty acids must be obtained through a species appropriate diet or supplementation.

EPA and DHA are necessary structural components of cell membranes. These functional, health-promoting fatty acids maintain the cell membrane fluidity and permeability needed for healthy functioning cells.

Essential Fatty Acids and their derivatives actually serve a number of major vital functions in our dog’s body (as well as our cat’s and our own human bodies). They are required for the transport and metabolism of both cholesterol and triglycerides. They are required for normal brain development and brain function. They are required in visual function (retina), brain and nerve function (synapses), and adrenal function. They are required in the structure of the membranes that surround each cell in our body. They stimulate metabolism, increase metabolic rate, increase oxygen uptake, and increase energy production. Omega-3s inhibit the production of prostaglandin. Prostaglandins play important roles in the development and progression of chronic inflammatory conditions such as rheumatoid arthritis (Research has shown that supplementing with omega 3 fish oils can result in a significant reduction in joint inflammation, this reduces morning stiffness and lowers the number of painful joints in rheumatoid arthritis patients both animal and human), lupus, inflammatory bowel disease and a variety of other inflammatory disorders including Kidney Disease. They even work to slow down growth of cancer cells!

It has been shown in human studies that the optimum ratio of Omega-6 to Omega 3 in the diet is 3:1. Since Omega-6 is available in grains, poultry and many cooking oils, over the last couple of decades the ratio in our own diet is estimated to be 20:1 — or even as high as 50:1 ! If you are still feeding processed pet foods you can well imagine how out of balance the ratio is in our kibble and canned pet food fed pets. Pet food and supplement manufacturers have begun adding Flax Seed or flax seed oil as their source of omega threes to their products… this is not necessarily a good thing for our carnivore companions.
If you are able to feed raw, pasture raised or raw meat to your dog, the need for supplemental Omega 3s is not even necessary. While many fish, pound for pound, are the best source of the healthiest omega-3s, any animal that eats grass has omega-3s. The reason why most beef, chicken, milk and eggs are so devoid of omega-3 anymore is that the factory farmed livestock are fed a factory diet of corn and other foods these animals are not designed to eat normally.

Wild animals and pastured or grass fed animals are ideal for your dogs and cat’s health. Compared with commercial products, they offer you more “good” fats, omega 3 fatty acids and fewer “bad” fats. They are richer in antioxidants; including vitamins E, beta-carotene, and vitamin C. Furthermore, they do not contain traces of added hormones, antibiotics or other drugs.

However, if you are not able to acquire wild game or grass fed meat, you can and should supplement with Omega 3s a few times a week.

Fish Oil vs. Flax Oil

I have found through research and study that the very best source of Omega 3s for our carnivore companions is in un-refined, wild fish oil and especially wild salmon oil. Farm raised salmon used for salmon oil has shown high levels of toxins that are not found in wild salmon. Not only is fish oil a more species appropriate food/supplement, for our carnivore companions but studies are giving sufficient evidence that oils such as flax, soy and canola, actually are thyroid toxic.

Flax oil contains alpha-Linolenic acid (ALA) and other fatty acids. ALA is actually the precursor of the Omega 3 oils (EPA and DHA) naturally found in fish oil. You see, ALA must be converted to EPA and DHA to be of any nutritional benefit at all. The fact is that ALA is not readily converted to EPA and is severely restricted in its conversion to DHA and its ability to be converted is lessened if the diet is already too high in omega-6. This conversion does not always take place, especially for carnivores who are not designed with the proper enzymes to digest and convert vegetables, seed or grain products in the first place. Even in people who are in less than optimal health or elderly are most often unable to convert the ALA to DHA and EPA.

You see, the body uses various enzymes to convert ALA to other omega-3s, and the process is not very efficient, especially in our carnivore companions and elderly humans. Estimates of the rate of conversion range from 5% to 25% in humans. In order to make sufficient amounts of EPA and DHA, one would need need to consume 5 or 6 times more ALA than if one relies on fish oil alone.

Fish oil, particularly Salmon oil EPA (from fish oil) converts naturally to series 3 prostaglandins, which have many benefits such as:

Regulating inflammatory responses (Skin and Joint)
Regulating immune function (which can help in fighting disease more effectively)
Regulating platelet stickiness
Regulating arterial muscle tone (which involves blood pressure regulation)

Active EFAs (EPA & DHA as found in Fish oil) go straight to work in your pet’s body, whereas inactive EFAs such as found in Flax as mentioned above, are unable to carry out their vital roles without first being converted by your dog to the active form. This conversion can only be carried out by enzymes, which your dog may or may not produce. If your dog does not produce those enzymes for any reason, those inactive essential fatty acids are not able to carry out their vital functions. This will lead to ill health.

Supplements which contain the activated omega 3 EFAs include Fish body oils such as Salmon oil and Cod Liver oil.

Supplements which contain the inactive omega 3 EFAs include flaxseed oil and hemp seed oil.

What about contamination and metals in fish oil?

Levels of various contaminants vary by species, by locale, and whether the fish are wild or farmed.

For example, mercury is lowest in salmon and highest in swordfish (see table below). In recent years, farmed salmon has been shown to contain more toxic chemicals than wild salmon

A diet that lacks sufficient omega 3s is the number one fatty acid associated problem caused by modern processed pet foods. This lack of the omega 3s allows the omega 6s to produce the whole range of problems caused by an excess of the omega 6s.

“In addition, the lack of the omega threes can be a potent cause of infertility in our breeding stock together with growth problems in young pups and kittens, and most importantly, problems with the development of the nervous system. This can result in early deterioration of vision and hearing, learning difficulties in puppies and kittens and behavioral problems in our pets that can continue throughout life.” Dr. Billinghurst

Fatty acids are essential components of cell membranes and are an integral component of the intercellular barrier in the stratum corneum. This barrier is formed by extrusion of lamellar granules containing phospholipids, glycosphingolipids, and free sterols that are produced by keratinocytes. Essential fatty acids cannot be synthesized and, therefore, must be supplied in the diet. Animals are unable to change one series of fatty acids to another, eg, omega-3 to omega-6. Dermatologic signs of fatty acid deficiency include a thin and discolored hair coat, scaly skin, sebaceous gland hypertrophy with hyperkeratosis of the sebaceous ducts and increased sebum viscosity, increased epidermal turnover rate, weak cutaneous capillaries, and decreased wound healing.

Fish Oil is more often recommended as a supplement for many pets as it improves a lot more than just the skin and coat – it helps a variety of different problems.

In dogs and cats, fish oil has been found to be useful for reducing inflammation in pets with allergic skin disease and arthritis. It has also been used successfully in animals in kidney failure. It may even help pets with heart disease and osteoarthritis.

Studies show that pets fed high doses of fish oil also have better control of cancer. Fighting Cancer with EFA’s In a diet supplemented with fish oil and the amino acid arginine appears to increase survival time in dogs with lymphoma, a cancer that affects white blood cells. Dogs with this kind of cancer, similar to non-Hodgkin’s lymphoma in humans, are easily treated, but as with humans, their cancer sometimes returns.

In one study, half of the dogs used – received a special “chow” (kibble) with the two supplements in it, and the other half ate “chow” with soybean oil added. The two diets or “chows” were identical in nutritional value, and formulated to be equally tasty to the dogs. All the dogs were being treated with the anti-cancer drug doxorubicin every three weeks, and were living at home with their owners.

The dogs were fed one of the kibbled food twice a day during and after their cancer treatment. The researchers report that compared to the control dogs, those who ate the supplemented kibble showed higher blood levels of two fatty acids called C20:5 and C22:6 that seem particularly effective in fighting cancer. Dogs with more of these fatty acids in their blood also tended to have more normal levels of lactic acid, which tends to accumulate in the blood when metabolism is disrupted in cancer patients.

The dogs with higher levels of these two fatty acids survived longer than those with lower levels, and had longer remissions, periods of time before their disease came back.

There is also research which has shown that some polyunsaturated fatty acids, like those found in fish oil, may help prevent the growth and spread of cancer tumors, and may help prevent cachexia — the devastating weight loss and muscle wasting seen in some cancer patients despite adequate nutrition. Likewise, arginine supplements have been reported to improve immune responses, and might help the body fight cancer.

Kidney Failure/Disease
Omega-3 fatty acids can increase beneficial (anti-inflammatory) prostaglandins; these prostaglandins can reduce inflammation in the kidney and improve blood flow to the kidneys (a vasodilatory effect). Since omega-3 fatty acids can also lower blood cholesterol and triglycerides, this effect can also benefit pets with kidney disease as dogs and cats with induced kidney disease have elevated levels of blood cholesterol and triglycerides.

Omega 3 fatty acids from marine fish oil have been shown to slow the progression of kidney disease in a clinical trial with dogs. The anti-inflammatory action of the Omega 3s may reduce kidney inflammation.

In pets with kidney disease, flax seed oil was NOT as effective as fish oil. While flax seed oil has been suggested by some and a substituted by many for fish oil, there is no evidence that it is effective when used for the same therapeutic purposes as fish oil. Unlike the case for fish oil, there is little evidence that flax seed oil is effective for any specific therapeutic purpose.

Note: Dietary supplements are designed to improve digestion, absorption and utilization of nutrition rather than to treat disease.


The Whole Dog highly Recommends using a wild salmon oil such as Only Natural Wild Alaskan Salmon Oil


Copyright 2003 – 2020 The Whole Dog, Whole Dog News Blog, Dr Jeanette Thomason, All rights reserved.

No part of this article may be reproduced in any form without the written consent of the Author/Publisher.

This article is intended to be educational. It is not intended to be a substitute for diagnosis or treatment from a veterinarian or other qualified animal health professional. Dr Jeanette (Jeannie) Thomason, The Whole Dog, Whole Dog News, does not assume any legal responsibility.

*Cancer 2000;88:1916-1928
Am. J. Clinical Nutrition, September 1999; 70: 560 – 569
Simopoulos AP, Kifer RR, Martin RE, Barlow SM, eds. Health effects of 3 polyunsaturated fats in seafoods. World Rev Nutr Diet 1991;66:1-592.

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