The Skinny on Fatty Acid Supplements for Pets

Do omega-3 supplements really work? Are they worth the trouble? Here’s my take.

By: Maufdi
What’s the skinny on fatty acids? Photo: Maufdi

Clients ask me about supplements all the time. Do they really work? Are they worth the trouble? Which brand should I buy? How much should I give? Can I give my dog what I take?

So many questions. So little evidence!

Fish oil and glucosamine top the popularity list in supplements. Today, I’m all about fish oil, a supplement with a broad array of potential benefits. Although research continues about the benefits of fish oil, we are also learning that fish oils are not all the same.


As with all supplements out there, claims by manufacturers and advocates alike are often overblown, and regulation and quality control of most supplements is sadly lacking, both for human supplements and those labeled for animals.

Fish Oil? Fatty Acids? Sounds Disgusting

Fish oil contains fatty acids called omega-3s. Anything named “fatty” and “acid” sounds like a bad stomach ache, but don’t let the name fool you. Omega-3 fatty acids, specifically EPA and DHA, can be very beneficial.

Omega-3s are helpful in supporting numerous normal body functions in animals. They also help in certain inflammatory processes:

  • Skin: Veterinarians have been prescribing omega 3s for skin for a long time. Fatty acids improve the normal or average skin and coat of your pets as well as help to control many dermatologic diseases such as allergic skin disease and autoimmune skin diseases, to name a few.
  • Joint health: Fatty acids may keep joints healthy and help with the inflammation associated with arthritis.
  • Cardiovascular health
  • Kidney function
  • Nervous system and retinal development

Omega-3s may support animals with inflammatory bowel disease, certain cancers and cognitive health.

In short, fish oil may be beneficial in many inflammatory conditions, plus fat metabolism and lipid disorders.

There’s Something Fishy About Fish Oils

As research continues both in the human field and in the veterinary field, more and more evidence is surfacing about the wide discrepancy in quality of fish oil supplements.

Because labels are confusing (possibly on purpose) and because the manufacturing of supplements is largely unregulated, be wary before you grab a bottle of fish oil in a big box store that looks like a great deal.


This video with Dr. Jim Humphries offers more information about the benefits and sources of omega-3s:

Which Fish Oil Should I Buy?

Although reading labels is a good thing to do, fish oil labels stink!

The amounts of those omega-3s (EPA and DHA) and how readily available they are are key, and most labels don’t tell you the important stuff. Research has found that label dosing recommendations for many veterinary omega-3 soft gels are seldom found at the levels advertised.

For some products, as much as 5 to 6 times the label dose would be required to reach a beneficial dose. If you have to use 5 times more softgels than the label suggests, you aren’t saving any money. If you’re giving what the label says but the product is deficient, you’re not doing your pet any good.

The marketing and labeling of human over-the-counter fish oil is also incredibly misleading. It is impossible for most pet caretakers to interpret labels regarding levels of EPA and DHA, and then try to dose that correctly for their itchy canine friends. Even if the amounts are right, is the fish oil capsule made in a way that gets absorbed, works and is free of toxins?

Fish Oil Is Only as Good as the Fish It Comes From

When it is making a fish oil supplement, what fish does the company use? Where does it get it? How does it process it?

Does the company test for heavy metals and other toxins? After processing, has the fish oil remained viable or have the beneficial omega-3 fatty acids been lost to oxidation?

Are you going to get this critical information from the label? No, you are not.

  1. Salmon has been the primary type of fish used in the past, but salmon has been overfished, and heavy metal toxicity has become a concern.
  2. Farm-raised salmon is easy to find, but higher levels of PCBs, parasites, chemicals, antibiotics and fewer omega-3s thanks to no wild diet make farm-raised salmon less desirable as a source for fish oil.
  3. Wild, non-predatory, smaller and more easily renewable high-fat-content fish such as anchovies and sardines are great sources of fish oil.
  4. Fish oils should be tested for heavy metals, microbial content and other contaminants. Many fish oil products are not screened for these toxins.

Why Not Use Discount Fish Oil?

  • Quality is extremely variable among human and veterinary OTC products.
  • Calculating the correct canine dose of omega-3s (EPA AND DHA) is difficult.
  • The form of the fish oil may not be indicated. Triglycerides? Ethyl esters? The “good stuff” is not always bio-available in many of these forms. You or your dog might have to down a third of the bottle before you are getting enough omega-3s.
  • The fish source and husbandry practices are not commonly indicated.

Supplements Do Not Replace Primary Drugs

Supplement means exactly that: You are supplementing a healthy diet and lifestyle with fish oil benefits, or you are supplementing other medications with fish oil in the treatment of a disease.

Fish oil will not cure your dog’s skin allergies, but it can help. In dermatological cases where veterinarians recommend fish oil frequently, a high quality of omega-3s can lessen the use of other drugs that may be needed but which have side effects, such as steroids.

If inflammation is controlled more naturally with fish oil, the greatest benefit is that your pet may feel better! For the cardiac, kidney or aging patient, fish oil may support many organ systems.

Frequently Asked Questions About Fish Oil Supplements

What is the recommended dosage of EPA/DHA for dogs and cats?

180 mg of EPA and 120 mg DHA per 10 pounds of body weight per day


Can I give flaxseed oil instead of fish oil?

It is not easy or reliable to predict how and in what amounts flaxseed oil metabolizes to EPA/DHA. Flaxseed oil is not routinely recommended.

Can I use cod liver oil?

Cod liver oil has a lot of Vitamin A and D, can have a high calorie content, and giving the correct amount of oil to get the correct dosage of omega-3s may not be easy.

Can you recommend a veterinary brand of fish oil?

A survey of veterinary dermatologists, naturopathic practitioners, and internal medicine specialists recommended a few reliable products:

This list is not exclusive, but these companies tend to be highly reliable and support their products with lots of data and transparency.

When you are giving a supplement, you are not going to see a magical effect overnight. To promote healthier skin and coat, for instance, or to improve inflammation in allergic skin disease, you need to commit to using omega-3s for at least 6 to 8 weeks. If you are using a poor-quality product or under-dosing your pet, you will be wasting time and money.

There are a lot of fish in the ocean. You want the ones sporting those really smokin’ omega-3s!


This pet health content was written by a veterinarian.