Omega 3 for Dogs: Benefits, Sources and Does Your Dog Really Need it Adding in?

Omega 3 is one of the most talked-about nutrients in dog nutrition.

It is linked with joint health, skin and coat condition, brain development and the body's inflammatory response, so it's easy to see why bottles of salmon oil and fish oil have become such common additions to dog bowls.

But there is one important point that often gets missed:

Not all omega 3s are the same – and more omega 3 isn't automatically better.

If your dog already eats a complete and balanced food, they may already be getting an appropriate amount from their diet. And if additional omega 3 would be useful, the type, source and dose matter far more than simply choosing a bottle with “omega 3” written on the front.

Before adding another supplement to your dog's bowl, it's always worth looking at their whole diet first. 

So, what exactly should dog owners know about omega 3?

What is omega 3?

Omega-3 fatty acids are a family of polyunsaturated fats.

The three names you're most likely to see are:

• ALA – alpha-linolenic acid

• EPA – eicosapentaenoic acid

• DHA – docosahexaenoic acid

ALA is commonly found in plant ingredients such as:

• Flaxseed or linseed

• Hemp

• Chia seeds

• Certain other seeds and plant oils

EPA and DHA are longer-chain omega-3 fatty acids traditionally associated with marine sources such as oily fish and fish oils.

They can also be obtained directly from certain species of microalgae, which is particularly useful when looking for a vegan omega-3 source.

And this distinction matters because ALA, EPA and DHA aren't simply interchangeable versions of the same nutrient.

Flax and hemp aren't the same as marine omega 3

Flax, hemp and chia are often described as excellent sources of omega 3.

They are sources of omega 3 – but primarily ALA.

Dogs can convert some ALA into longer-chain fatty acids such as EPA, but the conversion through to DHA is limited and inefficient.

Research looking at flaxseed oil supplementation in dogs found that ALA and EPA could increase, but DHA did not significantly increase.

Another study comparing flaxseed oil with a marine source of EPA and DHA found a significant increase in the dogs' Omega-3 Index when preformed EPA and DHA were supplied, while flaxseed oil did not produce the same effect.

That doesn't make flaxseed or hemp “bad”.

They can be nutritious ingredients and have other benefits. Ground flaxseed, for example, also provides fibre.

You can read more about why different types of fibre matter in our guide to fibre for dogs and digestive health. Why Fibre Is Important for Dogs

The important distinction is this:

If you're specifically trying to increase EPA and DHA, adding flaxseed or hemp oil isn't equivalent to supplying EPA and DHA directly.

What do EPA and DHA do for dogs?

EPA and DHA become incorporated into cell membranes throughout the body and can influence a number of biological processes, including inflammatory signalling.

DHA is also particularly important during growth, including development of the brain and eyes.

There are several situations where EPA and DHA have attracted particular interest.

Joint health and osteoarthritis

Joint disease is probably one of the better-supported reasons for considering additional EPA and DHA.

A randomised, double-blind, placebo-controlled trial involving dogs with osteoarthritis found improvements in measures of discomfort, lameness and joint severity in dogs receiving EPA and DHA compared with placebo.

Omega 3 doesn't replace veterinary treatment, appropriate pain relief, sensible exercise or keeping a dog at a healthy weight.

It may, however, form one part of a wider joint-management plan.

Skin and coat health

Essential fatty acids are important for maintaining healthy skin and coat.

Omega-3 supplementation has also been investigated in dogs with inflammatory skin conditions, although the results aren't as simple as “give fish oil to every itchy dog”.

Persistent itching, paw licking, recurrent ear problems or inflamed skin can have many different causes.

If your dog has suspected food allergies or intolerances, read our guide to hypoallergenic treats and sensitive dogs rather than assuming a supplement will fix the underlying problem. Best Hypoallergenic Dog Treats for Dogs with Allergies

Puppies and brain development

DHA has an important role during growth and development, particularly within the nervous system and retina.

This is one reason appropriately formulated puppy foods will often contain a source of DHA.

However, that does not mean owners should automatically add DHA supplements to a complete puppy food.

Growing dogs need nutrients supplied in carefully controlled amounts. Adding supplements without knowing what the existing food contains can alter the nutritional balance.

What about vegan omega 3 for dogs?

This is an area where there is often confusion.

A vegan omega-3 supplement does not have to mean flaxseed or hemp oil.

Certain microalgae can supply DHA and, depending on the species and formulation, EPA too.

This makes algae particularly interesting for owners looking for a direct, animal-free source of long-chain omega 3.

When choosing a vegan omega supplement, don't just look for:

“Rich in plant-based omega 3.”

Turn the bottle around and look for the actual amounts of:

EPA: ___ mg

DHA: ___ mg

Some algal products primarily contain DHA, while others provide both EPA and DHA.

What matters is whether that product provides the fatty acids you're actually trying to add.

Why I wouldn't automatically add salmon oil to every dog's food

Salmon oil itself isn't inherently bad.

It can be a useful source of EPA and DHA.

The problem is the “just add a pump of salmon oil” approach.

Before adding it, there are several things worth considering.

1. How much EPA and DHA does it actually provide?

A tablespoon of oil or a “pump” isn't a nutritional dose.

The useful information is the number of milligrams of EPA and DHA being supplied.

A 2025 analysis of 11 canine fish-oil supplements found considerable variation in EPA and DHA content between products and reported several instances where measured concentrations did not closely match label claims at all.

That doesn't mean all fish oils are unreliable or even that they are “bad”

It does mean it is worth choosing transparent products that clearly state their EPA and DHA concentrations rather than simply advertising “100% salmon oil” or “high in omega 3”. It may just mean you are adding fat to your dogs food without the added benefits.

2. You're adding calories

Oil is extremely calorie dense.

Fat supplies around 9 kcal per gram, so regularly pouring oil over meals can make a meaningful difference to a dog's total calorie intake.

This is particularly relevant for:

• Small dogs

• Overweight dogs

• Dogs on a weight-loss programme

• Dogs already receiving lots of treats or toppers

If weight is an issue, read our guide to helping your dog lose weight. How to Help Your Dog Lose Weight

A supplement shouldn't accidentally undermine the rest of your dog's diet.

3. Omega-3 oils are vulnerable to oxidation

EPA and DHA are polyunsaturated fats, which means they are relatively vulnerable to oxidation.

Exposure to heat, oxygen and light can affect oil quality over time.

Look at:

• Packaging

• Storage instructions

• Expiry dates

• How quickly the bottle will be used once opened

For a small dog, buying an enormous bottle that remains open for months may not be the best choice.

4. Your dog's food may already contain EPA and DHA

This is one of the biggest reasons not to supplement automatically.

Many complete foods already contain fish oil, fish meal, algal ingredients or other sources of EPA and DHA.

Some therapeutic diets for joints, skin or kidney conditions may contain considerably higher levels.

Before adding more, find out what you're already feeding.

When might a dog benefit from extra omega 3?

There isn't one answer for every dog.

Additional EPA and DHA might be considered when:

• The current diet provides relatively little EPA and DHA.

• A vet has recommended omega 3 as part of managing osteoarthritis.

• A particular medical condition warrants a therapeutic amount.

• A professionally formulated home-cooked diet needs a specific omega-3 source adding in

• A dog's life stage means a particular DHA intake is required.

• A qualified professional has assessed the overall diet and identified a reason to supplement.

The important word here is specific.

Rather than asking:

“Is omega 3 good for dogs?”

Ask:

“Does my dog need more omega 3 than they are currently getting – and if so, which type and how much?”

7 questions to ask before adding an omega-3 supplement

Before putting anything else into your dog's bowl, ask yourself:

1. Why am I giving this supplement?

What are you actually hoping it will achieve?

2. What does my dog's current food already contain?

Check the complete diet first.

3. Which type of omega 3 am I buying?

ALA is not the same as EPA and DHA.

4. Does the label tell me the EPA and DHA content?

“Contains omega 3” isn't enough information.

5. How many additional calories am I feeding?

Remember that oil is almost entirely fat.

6. Is additional fat appropriate for my dog?

Dogs with gastrointestinal disease, previous pancreatitis or other health conditions may require more careful dietary management.

7. What is the appropriate dose for my dog?

Therapeutic omega-3 intake depends on your dog's weight, diet and the reason it is being used.

Don't copy another dog's dose from social media.

For more information about when supplements may – and may not – be appropriate, The Canine Dietitian has a detailed guide to whether your dog really needs supplements. Does Your Dog Really Need Supplements?

Frequently Asked Questions About Omega 3 for Dogs

Is flaxseed a good source of omega 3 for dogs?

Flaxseed is a good source of the omega-3 fatty acid ALA. However, if you're specifically trying to provide EPA and DHA, preformed sources such as fish or appropriate microalgae are more direct because dogs have limited conversion of ALA to the longer-chain omega-3 fatty acids.

Is hemp oil the same as fish oil for dogs?

No. Hemp oil primarily provides ALA, whereas fish oil normally provides EPA and DHA directly. They shouldn't automatically be considered interchangeable.

Can dogs have vegan omega 3?

Yes. Certain algal oils provide DHA and some provide both EPA and DHA, making them useful animal-free sources of long-chain omega-3 fatty acids.

Should every dog have salmon oil?

No. A dog eating a suitably formulated complete diet may already receive adequate essential fatty acids. Whether additional EPA and DHA are useful depends on the individual dog, their diet and what you're trying to achieve.

Can too much omega 3 be bad for dogs?

Potentially. Supplements add calories and can alter the overall fatty-acid intake of the diet. Higher therapeutic doses should be used appropriately, particularly in dogs with medical conditions or those taking medication.

The bottom line

Omega 3 can be extremely useful in canine nutrition.

But good nutrition isn't about adding every nutrient that has a health benefit to your dog's bowl. Just because your dog can eat something doesn’t mean they should.

It's about supplying the right nutrient, in the right form, in the right amount, for the right dog.

Flax and hemp provide predominantly ALA.

Marine oils provide EPA and DHA directly.

Microalgae can provide a vegan source of DHA and, in certain products, EPA too.

And salmon oil can be perfectly appropriate – but your dog doesn't automatically need a daily pump simply because omega 3 has a healthy reputation.

Check the diet first. Identify why you want to supplement. Look at EPA and DHA rather than marketing claims. Then decide whether adding more actually makes nutritional sense.

References

1. Purushothaman D, Brown WY, Wu SB & Vanselow B. (2011). Evaluation of breed effects on n-3 PUFA metabolism with dietary flaxseed oil supplementation in dogs. British Journal of Nutrition, 106(S1). Flaxseed supplementation increased ALA and EPA but did not significantly increase DHA. View study on PubMed

2. Dominguez T et al. (2021). Enhanced omega-3 index after long- versus short-chain omega-3 fatty acid supplementation in dogs. Veterinary Medicine and Science, 7, 370–377. Read the open-access study

3. Vandeweerd JM et al. (2016). A prospective, randomized, double-blind, placebo-controlled evaluation of EPA and DHA in dogs with osteoarthritis. Dogs receiving EPA+DHA showed improvements in clinical measures compared with placebo. View osteoarthritis study on PubMed

4. Dahms I et al. (2019). Safety of a novel feed ingredient, algal oil containing EPA and DHA, in a gestation-lactation-growth feeding study in Beagle dogs. PLOS ONE. Plasma EPA and DHA increased significantly and dose-dependently with the algal-oil diets. View algal EPA and DHA study

5. Souza CMM et al. (2019). Microalgae Schizochytrium sp. as a source of docosahexaenoic acid (DHA): effects in dogs. Animal Science Journal, 90(12), 1567–1574. View microalgae DHA study

6. Ober LR, Larsen JA, Hoffman LE, Puschner B & Fascetti AJ. (2025). Analysis of selected nutrients and contaminants in fish oil supplements for dogs. Topics in Companion Animal Medicine, 65, 100949. EPA and DHA concentrations varied between products and several samples did not closely meet their label claims. View fish-oil supplement study