Why EPA and DHA matter more than "total omega-3"

Short answer: "Total omega-3" can include ALA from plant oils such as flaxseed, which dogs convert into EPA and DHA very inefficiently. EPA and DHA are the marine fatty acids that skin and coat research actually focuses on. Look for them listed separately in milligrams per serving — if a label gives only a combined omega-3 figure, you cannot tell what you are getting.

Pick up almost any omega supplement for dogs and you'll find a number on the front: 1,000 mg Omega-3. It looks like a lot. It usually isn't the number that matters.

Omega-3 is a category, not an ingredient

"Omega-3" describes a family of fatty acids, not a single compound. Three of them show up in pet supplements:

  • ALA (alpha-linolenic acid) — comes from plants: flaxseed, chia, canola
  • EPA (eicosapentaenoic acid) — comes from marine sources: fish, algae, krill
  • DHA (docosahexaenoic acid) — also marine

All three are technically omega-3. They are not interchangeable in the body.

Why can't dogs just use ALA from flaxseed?

Dogs can convert ALA into EPA and DHA, but the process is slow and inefficient. Most of the ALA a dog eats is simply used for energy rather than converted.

This matters commercially, because flaxseed oil costs a fraction of what marine oil costs. A manufacturer can add a large amount of flaxseed, declare a big "total omega-3" figure on the label, and stay entirely accurate — while delivering very little of the fatty acids that research on skin and coat condition actually focuses on.

What does this look like on a real label?

Here is a real pattern we encountered while developing our own formula. An early supplier sheet listed:

  • Omega-3: 250 mg
  • Salmon oil: 100 mg
  • Flaxseed: listed among the inactive ingredients

One hundred milligrams of salmon oil provides roughly 20 to 30 mg of EPA and DHA combined. So where did the other 220 mg of "omega-3" come from? The flaxseed. The label was accurate. It was also, for our purposes, close to meaningless.

We asked. The supplier confirmed it, corrected the sheet, and we changed the formula. The full account of that decision is in what we put on our label, and why.

Does the amount of fish oil tell you how much EPA and DHA you get?

No. Not all fish oil is equal. Standard fish oil might be 18% EPA and 12% DHA — what the industry calls an 18/12 oil. Natural salmon oil is often lower, and skewed toward DHA rather than EPA. Concentrated oils can run 50% or higher.

This means two products can both say "400 mg fish oil" and deliver completely different amounts of EPA and DHA. The oil amount tells you almost nothing on its own.

Concentration is only half the picture, either. An oil also has to still be fresh by the time it reaches the dog — see fish oil freshness and why some omega chews smell.

What should I look for on the label?

When you're comparing supplements, three questions cut through most of the noise:

  1. Are EPA and DHA listed separately, in mg? If a label only gives "total omega-3", you cannot tell what you're getting.
  2. Is there a plant oil in the ingredients? Flaxseed, chia and canola are fine ingredients. They just shouldn't be counted toward an EPA/DHA figure.
  3. What is the amount per serving, not per chew? Serving sizes vary. Per-chew figures are easy to make look larger. Our guide to reading a pet supplement label covers the rest.

What we do

Our Skin + Coat Soft Chews declare EPA and DHA separately, in milligrams, per daily serving — 72 mg and 48 mg. Not a combined omega-3 figure. Not a percentage. The actual numbers, from a marine oil, with the plant oils counted separately if they're there at all.

We think that should be normal. It currently isn't.

Further reading

These statements have not been evaluated by the Food and Drug Administration. This product is a supplement for supplemental feeding only and is not intended to diagnose, treat, cure, or prevent any disease. Consult your veterinarian before use.

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