The Dog Food Project
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Essential Fatty Acids


Essential fatty acids (EFAs) are fats that must be supplied in the diet because the body cannot produce them. They are required for normal growth and functioning of the cells, muscles, nerves, and organs and the production of prostaglandins (hormone-like substances which are key to many important processes). Deficiencies of EFAs are linked to a variety of health problems, including heart disease, cancer and diabetes. Essential fatty acids are divided into two groups, Omega-3 and Omega-6. The numbers in the name indicate the first carbon double bond position on the fatty acid chain. All essential fatty acids are polyunsaturated, the 3 and the 6 mean that the first double bond is either 3 or 6 carbons in from the end. I won't go further into the chemical side of things since that is not the subject here.

Omega-6 Fatty Acids:

  • Linoleic acid (LA), found in corn, soy, canola, safflower and sunflower oil, whole grains, body fat of poultry (chicken, turkey, duck etc.).
  • Arachidonic acid (AA), found in the body fat of poultry, lean meat, egg yolks and some fish oils.
  • Gamma linolenic acid (GLA), found in black currant seed oil, borage oil and evening primrose oil.
  • Dihomogamma linolenic acid (DGLA), found in organ meats like spleen, kidney and adrenals and metabolized from GLA.

Omega-3 Fatty Acids:

  • Alpha linolenic acid (ALA)), found in flaxseed oil and to a lesser extent, canola, soy, and walnut oils.
  • Eicosapentaenoic acid (EPA), found in cold water fish and their oil.
  • Docosahexaenoic acid (DHA), found in cold water fish and their oil.

Despite the fact that the AAFCO still does not recognize EFAs as essential nutrients, more and more manufacturers include them in their products and of course proudly advertise the fact. Don't let yourself get fooled though, it's not enough that a brand is just advertised as "contains [high levels of] Omega-3 and Omega-6 Fatty Acids" - they need to be present in sufficient amounts and in the proper ratio. As with all other ingredients, the manufacturers of lesser quality products try to get away as cheap as possible to maintain a large profit margin. Incorporating EFA's into a dog food is rather expensive in terms of ingredients as well as preservation, since especially the Omega-3's oxidize (and thus spoil) rather quickly.

Iams Company researcher Dr. Greg Reinhart recommends a ratio of Omega-6 to Omega-3 ranging between 5:1 and 10:1 (interestingly enough all Iams dry foods contain just that minimum ratio of 10:1, Eukanuba varieties range from 5:1 to 8:1 and average 7:1). Independent researcher Dr. Doug Bibus (formerly University of Minnesota) completed a fatty acid study with dogs and recommends a ratio between 2:1 and 4:1. Personally I believe that a quality food should contain a ratio of at least 7:1, the lower the better, especially if skin and/or coat problems are present. When my dog suffered from severe flea allergy dermatitis I switched to a food with a ratio of 2.5:1 and had great results within just a few weeks.

Proper ratios aside, the amounts are also important. You can have a decent ratio but there is no point at all if the amounts present in the food are too low to actually provide much or any benefit. All the better foods contain (depending on the ratio) at least 2.2% Omega-6's and 0.3% Omega-3's. There are very few exceptions where true quality foods do not fall within these numbers, but it shouldn't discourage you if your dog does well on them - you just might consider supplementing some EFAs to improve the diet. In addition to drastic improvements to skin and coat, high levels of Omega-3s improve cardiovascular health, fight inflammatory diseases, retard development of certain cancer cells, inhibit progression of kidney disease, enhance the immune system, reduce the symptoms of allergic dermatitis and reduce joint stiffness, which is especially beneficial for older dogs.

Depending on the presence of certain enzymes in the metabolism of the individual dog, fatty acids are considered either "active" or "inactive". If the dog produces the enzymes required to activate the inactive EFA's, it does not matter whether you supplement active or inactive forms. If a dog does not produce the required enzymes, or not enough of them, supplementation of active EFA's that do not require enzymes to be utilized is required.

  • Evening primrose oil, borage oil and black currant oil are considered sources of activated Omega 6 EFA's, while more common sources such as vegetable oils (canola, corn, soy), sunflower oil and safflower oil are inactive.
  • Cod liver oil and fish oils (salmon, herring etc.) supply activated Omega 3 EFA's, flax seed and hemp are inactive.

If you supply inactive sources and notice apparent benefits, there is no need to supply activated sources. If you started EFA supplementation with inactive sources relatively recently and do not notice associated changes within a time frame of several weeks, you might want to consider giving the active sources a try instead.

Decide for yourself if your dog is getting the proper amounts of EFAs and don't be afraid to supplement, but if you do, make sure you choose the right product. Most commercial diets contain plenty of Omega-6's from corn and other whole grains, corn-, sunflower- and other vegetable oils or the fat of various poultry, so don't add even more of them - instead try to decrease the ratio by adding Omega-3's. Deep water fish and flax seed, either as fresh product (fresh ground flax seed and fresh or canned fish, be very careful about feeding raw fish, not all kinds are safe for dogs!) or oils, are excellent choices. If your dog has kidney troubles or the breed is known to be prone to kidney disease, omit the flax and stick with the fish.

Omega 3 fatty acids oxidize rapidly and increase antioxidant requirements in the body. If you supplement, you should make sure the product you feed either has vitamin E added, or supply a vitamin E supplement separately.

While Omega-6 fatty acids are required for good health, excessive amounts of some of them, especially Arachidonic acid, are actually harmful, that is the reason a balance needs to be established. Oversupplementation of Omega-3's to an extent of causing health problems is virtually impossible, but if you give a fish oil supplement, be very careful to check whether it contains any vitamin A and D (cod liver oil does for example!) - they are already present in commercial dog foods and excessive amounts will result in toxicity. Consult your veterinarian before you start feeding any supplements.