Omega-3 for Dogs: The Best Sources, Honestly

Written by Lucy Fitzgerald, Founder, WYLDR. Reviewed by Katie McCaul, RNutr, The Pet Diet.

The short answer: Omega-3 for dogs means three fats: ALA from plants, and EPA and DHA from marine sources. EPA and DHA are the ones most studied in canine health, and dogs convert plant ALA into them only to a limited degree. The best food sources are oily fish, fish oils such as salmon oil, and algal oil. FEDIAF sets a minimum for puppies but not for adult dogs.

Omega-3 is one of the most talked-about nutrients in dog food and one of the most loosely used words on a label. "Contains omega-3" can mean a meaningful amount of the fats that have actually been studied in dogs, or it can mean a splash of something that technically qualifies. This guide explains the difference, ranks the real sources, and is straight about what the guidelines do and do not say.

What omega-3 actually is

In short: Omega-3 is a family of polyunsaturated fats. Three matter here: ALA from plants, and EPA and DHA from marine sources. They are not interchangeable.

Alpha-linolenic acid (ALA) is the short-chain omega-3 found in plant foods such as flaxseed, chia and rapeseed oil. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are the long-chain omega-3s found in oily fish, fish oils and marine algae.

The distinction matters more than most labels admit. When veterinary nutrition research talks about omega-3 in dogs, it is usually talking about EPA and DHA. Fish oils and their use in dogs and cats have been reviewed in the veterinary literature, including Bauer's 2011 review in the Journal of the American Veterinary Medical Association.

DHA in particular is a structural fat. FEDIAF's guidelines note that DHA accumulates in brain and retina tissue during gestation and early life, which is why the recommendation for growth exists at all.

The conversion problem

In short: The body can turn ALA into EPA and DHA, but in dogs the conversion is limited. That is why a plant omega-3 and a marine omega-3 are not equivalent, whatever the label implies.

This is the single most useful thing to understand about omega-3, and the reason "contains flaxseed" and "contains salmon oil" are not the same statement.

Mammals can convert ALA into EPA and then into DHA, but the pathway is inefficient. In dogs, the conversion is generally described in veterinary nutrition as limited. We have deliberately not put a percentage on that, because we could not find a canine study giving one that we would be willing to stand behind, and a made-up number is worse than no number.

The practical consequence is simple. If EPA and DHA are what you are after, a marine source gets you there directly.

What are the benefits of omega-3, and why add it if it is not essential?

Omega-3 fatty acids, particularly EPA and DHA, have anti-inflammatory effects in dogs through several biological mechanisms. EPA and DHA can alter cell-membrane fatty-acid composition and influence the production of inflammatory lipid mediators. They compete with arachidonic acid pathways and can result in the formation of eicosanoids and other signalling molecules that are generally less pro-inflammatory. EPA and DHA also serve as precursors for specialised pro-resolving mediators, including resolvins and protectins, which are involved in regulating the resolution of inflammation.

In canine research, these mechanisms have translated into measurable effects in some clinical settings. The most consistent evidence is in dogs with osteoarthritis, where diets or supplements providing EPA and DHA have been associated with improvements in some measures of mobility, weight-bearing and clinical signs. However, responses vary between studies, and omega-3 supplementation should not be interpreted as eliminating inflammation or treating its underlying cause.

What the guidelines actually say

In short: FEDIAF sets a minimum EPA plus DHA level for puppies. For adult dogs, it states that the information is insufficient to recommend a level at all.

This is worth reading twice, because almost no one selling omega-3 will tell you.

In its Nutritional Guidelines, September 2025 edition, FEDIAF, the European pet food industry federation, states that although there is increasing evidence of beneficial effects of omega-3 fatty acids, the current information is insufficient to recommend a specific level of omega-3 fatty acids for adult dogs.

For growth and reproduction, it does set a minimum: 0.05 g of EPA plus DHA per 100 g dry matter, equivalent to 0.13 g per 1,000 kcal metabolisable energy. The rationale given is that DHA accumulates in brain and retinal tissue during gestation and early life, and that puppies lose much of their conversion capacity after weaning.

So the honest position is this. For puppies, there is a number. For adult dogs, there is active research interest and no agreed requirement. Omega-3 is worth understanding and worth including in the conversation about a dog's diet. It is not a settled nutritional obligation with a figure attached, and anyone presenting it as one is running ahead of the guidance.

The best sources of omega-3 for dogs, ranked

In short: Oily fish and fish oils give you EPA and DHA directly. Algal oil does the same without the fish. Flaxseed and other plant sources give ALA only.

Oily fish. Salmon, sardines, mackerel and herring are the richest whole-food sources of EPA and DHA. Fed as a food, they bring protein and fat-soluble vitamins alongside the fats. Our guide to oily fish for dogs covers which ones suit and how to serve them, and can dogs eat salmon covers the most-asked one in detail.

Fish oils. Salmon oil, cod liver oil and generic fish oil concentrate the fats without the protein or bones. This is the most common supplement route. Quality varies enormously, and the important number on the label is the EPA and DHA content, not the total oil weight. Our guide to salmon oil for dogs covers what to look for.

Algal oil. Marine algae are where the fish get their EPA and DHA in the first place. Algal oil is a direct plant-free, fish-free source, which makes it useful for dogs that react to fish. It tends to cost more.

Green-lipped mussel. Contains omega-3 and is a genuine marine source. We are not going further than that here, because green-lipped mussel is usually marketed for joint support, which sits outside what this blog will claim.

Flaxseed, chia and other plant sources. These provide ALA. They are not useless, but they are a weaker route to EPA and DHA because of the conversion problem above. A food that lists flaxseed as its omega-3 source is not equivalent to one providing EPA and DHA directly, however the front of the pack reads.

Practical points on quality and safety

In short: Check the EPA and DHA figures rather than the total oil. Keep oils sealed and cool. Introduce gradually. Speak to your vet before adding omega-3 if your dog is on medication or has a health condition.

Omega-3 oils are fragile. They degrade with heat, light and air, which is why a bottle that has been open on a warm shelf for months is not the same product it was when it was sealed. Buy a size you will actually get through, keep it closed and cool, and trust your nose: if it smells sharply off, it is.

On the label, look for stated EPA and DHA content. "Salmon oil" tells you the source. It does not tell you the dose of the fats you are actually buying.

We have not given mg per kilo dosing figures here. The figures circulating online come mostly from sellers rather than from guidelines, and this is exactly the sort of number worth getting from your vet or a qualified nutritionist for your specific dog rather than from a blog.

Too much omega-3 is not harmless. Excess can loosen stools and adds fat and calories. If your dog is on medication, particularly anything affecting clotting, or has a condition such as pancreatitis, check before adding an oil.

Where WYLDR fits

WYLDR's Every Dog Every Day contains salmon oil as one of its five ingredients, which is a marine source of EPA and DHA rather than a plant source of ALA. That is a statement about what is in the tub. It is not a promise about what it will do for your dog, and the specific analytical figures will be published once the finished-product certificate of analysis is complete. If you want the wider context on why a daily supplement exists at all, our guide to do dogs need supplements sets it out.

Frequently asked questions

What does omega-3 do for dogs?
Omega-3 fats, particularly the long-chain EPA and DHA found in marine sources, are among the most studied fats in canine nutrition. DHA is a structural fat that accumulates in brain and retinal tissue during early development, which is why FEDIAF sets a minimum for puppies. For adult dogs, FEDIAF states the current information is insufficient to recommend a specific level.

What is the best source of omega-3 for dogs?
For EPA and DHA specifically, marine sources are the most direct: oily fish such as salmon, sardines and mackerel, fish oils such as salmon oil, and algal oil. Plant sources such as flaxseed provide ALA, which dogs convert into EPA and DHA only to a limited extent.

Is flaxseed a good source of omega-3 for dogs?
Flaxseed provides ALA, a short-chain omega-3. Dogs convert ALA into the long-chain EPA and DHA only to a limited degree, so flaxseed is a weaker route to those specific fats than a marine source. It is not the same thing as fish oil, whatever a label implies.

How much omega-3 does a dog need?
FEDIAF's 2025 guidelines set a minimum of 0.05 g EPA plus DHA per 100 g dry matter for growth, equivalent to 0.13 g per 1,000 kcal. For adult dogs, FEDIAF states there is insufficient information to recommend a specific level. Dosing for an individual dog is a question for your vet or a qualified nutritionist.

Can dogs have too much omega-3?
Yes. Excess can loosen stools and adds fat and calories to the diet. Dogs on medication, particularly anything affecting clotting, and dogs with conditions such as pancreatitis should only be given omega-3 oils on veterinary advice.

Is fish oil or algal oil better for dogs?
Both provide EPA and DHA. Algal oil is the original source, since fish acquire these fats by eating algae, and it suits dogs that react to fish. Fish oil is usually cheaper. What matters is the stated EPA and DHA content and the freshness of the product, not the name on the front.

Sources

• FEDIAF, Nutritional Guidelines for Complete and Complementary Pet Food for Cats and Dogs, September 2025 edition (adult dog position, growth minimum, DHA rationale): link
• Bauer JE. "Therapeutic use of fish oils in companion animals", JAVMA 239(11):1441-1451 (2011, peer-reviewed): link
• National Research Council (NRC), Nutrient Requirements of Dogs and Cats, The National Academies Press (2006): source for the limited ALA-to-EPA/DHA conversion in dogs, supplied by Katie McCaul
• Burron S, et al. "The balance of n-6 and n-3 fatty acids in canine, feline, and equine nutrition", J Anim Sci 102:skae143 (2024, peer-reviewed): link
• LeBlanc CJ, et al. "Effects of dietary supplementation with fish oil on in vivo production of inflammatory mediators in clinically normal dogs", Am J Vet Res 69(4):486-493 (2008, peer-reviewed): link
• Liu T, et al. "n-3 polyunsaturated fatty acids prevents atrial fibrillation by inhibiting inflammation in a canine sterile pericarditis model", Int J Cardiol 153(3):298-303 (2011, peer-reviewed): link
• Ontsouka EC, et al. "Fish-meal diet enriched with omega-3 PUFA and treatment of canine chronic enteropathies", Eur J Lipid Sci Technol 114(2):183-190 (2012, peer-reviewed): link
• LeBlanc CJ, et al. "Effects of dietary fish oil and vitamin E supplementation on canine lymphocyte proliferation", Vet Immunol Immunopathol 119(3-4):180-188 (2007, peer-reviewed): link
• Gomes RA, et al. "Protective effects of omega-3 fatty acids in dogs with myxomatous mitral valve disease stages B2 and C", PLOS ONE 16(8):e0254887 (2021, peer-reviewed): link