Everything You Need to Know About Fish Oil for Dogs - Bonnie and Clyde Pet Goods

Everything You Need to Know About Fish Oil for Dogs

If you have a television or internet connection, you have probably heard at some point in the last few years about the many benefits of omega-3 fatty acids for humans. Unsurprisingly, it’s also great for your dogs! Doctor Pugman put together some information for you.

Doctor Pugman

Benefits of Omega-3 Fish Oil for Dogs

Omega-3 fatty acids, also referred to as n-3 fatty acids, are polyunsatured fatty acids (PUFAs for short). There’s three commonly supplemented types of omega-3 fatty acids:

  • ALA (α-linolenic acid)
    • Typically found in plant oils, with sources such as flaxseeds, walnuts, hemp, and other seeds
  • EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid)
    • Found in marine oil, sources: fish, eggs, squid, and krill
    • Typically come together

Your dog can’t produce their own omega-3, so they need to get this from their diets. Making sure your dog gets the right amount of omega-3 fatty acids can have a number of positive effects on their health.

Skin and Coat Health

Omega-3 fatty acids have a proven benefit to skin/coat conditions through an anti-inflammatory effect. Dogs with allergy symptoms (atopic dermatitis) such as itching, scratching, hair loss, and chewing may benefit from omega-3 supplementation.

Straight from the lab coats:

  • “Essential fatty acids have a structural role in cell membranes … and are vital for maintaining normal skin structure and function.” [1]
  • “…a placebo-controlled, double-blind, cross-over study has demonstrated a clear benefit of high dose (n-3) fatty acids in the management of pruritic skin disease.”
  • A 1995 survey of veterinary dermatology specialists found that: >90% of responders believed dietary fatty acid supplements to be useful” [2]
  • “When compared to the corn oil control over time, marine oil supplementation significantly improved pruritus (P < 0.02), alopecia (P < 0.05) and coat character (P < 0.001). This study demonstrates the effectiveness of high doses of marine oil as an alternative anti-inflammatory for canine pruritic skin disease.” [3]

Longevity and Cardiovascular Health

Studies have shown that dogs receiving omega-3 supplements benefited from longer lives and increased cardiovascular health. A diet high in omega-3 was shown to reduce inflammatory proteins and fatty acids in the body.

  • “The results of this study also show a significantly longer survival time for dogs receiving n-3 fatty acid supplementation; n-3 fatty acid supplementation reduces inflammatory cytokines and eicosanoids, reduces muscle loss, and has antiarrhythmic effects.” [4]

Neurological and Trainability

A 2006 study found that pregnant dogs fed a diet high in DHA during pregnancy and lactation were associated with improved neurological development in their puppies. They also found that: “feeding diets or supplements containing DHA may improve memory or learning in young dogs.” [5]

A 2004 study found that puppies with a high-DHA diet appeared to be more trainable than puppies with a low-DHA diet.

  • “…over twice as many puppies (68%) from the high-DHA group passed the test compared to the low-DHA group (30%).” [6]


A randomized, double-blind, controlled clinical trial found that dogs fed a food extremely high in omega-3 fatty acids and lower in omega-6 fatty acids had increased mobility and improved arthritic condition.

  • “According to owners, dogs fed the test food had a significantly improved ability to rise from a resting position and play at 6 weeks and improved ability to walk at 12 and 24 weeks, compared with control dogs.” [7]


The suspected mechanism that makes omega-3 fatty acids so beneficial is that they compete with arachidonic acid (AA), which is an omega-6 fatty acid usually derived from linoleic acid.

This may help to reduce the amount inflammatory metabolites in an animal’s body. A 2008 study suggested that: “Results supported the use of EPA- and DHA-enriched diets as part of anti-inflammatory treatments for dogs with chronic inflammatory diseases.” [8]

  • “The eicosanoids produced from omega-3 fatty acids are less inflammatory than those produced from AA.”

Fish, Not Flax! (ALA vs EPA/DHA)

Alpha-linolenic acid (ALA) is one form of omega-3 fatty acids. It’s primarily found in plant-based oils (canola, flaxseed, soybean, and walnuts).

Experts agree that ALA is an inefficient way to supplement omega-3 fatty acids to your dog, as it needs to be converted to EPA and DHA in their bodies.

  • “Diets containing only ALA as n-3 source or mixtures of ALA and fish oil may not perform as effectively in this regard when included on an equivalent weight basis (23-25) One reason for this is the inefficient rate of conversion of ALA to EPA (26).” [9]
  • “Marine oil sources provide EPA and DHA, which are more effective in dogs and cats than ALA (which is not significantly converted to EPA or DHA).” [10]

Cold-Water Oily Fish Blends vs Salmon vs Cod Liver vs Krill vs Pollock

In terms of marine oils, there are many different types and sometimes it can be difficult to select which one to give to your dog.

Here’s a few factors that may help your decision.


In terms of EPA and DHA concentration, here’s what some leading oils on the market currently offer:

  • Sardine, Herring, Mackerel, Anchovy Blends: 18% EPA, 12% DHA
    • This is pretty much the highest concentration available naturally, without having to run the oil through a chemical synthesis to artificially increase the amount of EPA/DHA
  • Salmon Oil: 10% EPA, 11% DHA
    • Unless otherwise specified, it’s very likely that your salmon oil is from farmed salmon. Farmed salmon are fed antibiotics and unnatural commercial diets which may include unwanted byproducts from other animals and GMOs
  • Cod Liver Oil: 9% EPA, 11% DHA
    • Cod liver oil almost always includes vitamins A and D, which may increase the risk of hypervitaminosis in your dog
  • Krill Oil: 11% EPA, 5% DHA
    • Krill is not a sustainable product and offers a lower concentration of EPA and DHA
  • Pollock Oil: 6% EPA, 12% DHA

When deciding on a fish oil supplement to feed your dog, you should use one with a higher concentration of EPA and DHA. This will minimize the amount of extra calories they will take in their diet, reducing their risk of obesity.

Farmed Fish Or Wild-Caught

We recommend looking for one that is made specifically from wild-caught fish. It’s a safe assumption that if a brand doesn’t say whether their oil is from wild-caught fish or not, it’s probably farmed. Companies are typically proud to announce to the world that their oil is produced from wild fish.

Farmed fish are often fed terrible diets, exposed to antibiotics and poor living conditions. Ironically enough, they are usually fed fishmeal and fish oil made from smaller oily species such as mackerel, sardine, herring, and anchovy.

“Human” And “Pharmaceutical” Grade

Neither “human grade” nor “pharmaceutical grade” hold any legal meaning whatsoever. We’ve put “human grade” on our label to indicate the quality of our oil, and that our product is actually made from an oil that was intended for humans. The term “pharmaceutical grade” is in very gray ethical territory in our opinion, as it suggests that a product has a drug component or effect.

Delivery Methods

Finally, it’s important to choose a product that makes serving the oil to your dogs convenient. Complex, inconvenient products are often neglected and ignored after the first few uses.

Gel-caps can be very convenient for some whose dogs are happy to eat them mixed in with food or “pill pocket treats.” Some people elect to break open the gel and pour the liquid directly on their dogs’ food.

Liquid oils can be messy unless the product comes with a quality pump or pouring cap. These products have the advantage of being simpler to serve if your dog doesn’t like pills or gel caps.

Triglyceride (TG) vs Ethyl Ester (EE) Oils

The maximum concentration of omega-3 essential fatty acids can reach in a fish oil supplement naturally is approximately 30%.

After extracting oil from the fish, the oil is in a natural triglyceride (TG) form. Fish oil supplement manufacturers that wish to increase the concentration of omega-3s per gram of oil may run the oil through a process called micro distillation. This has the potential to increase the concentration of omega-3 up to 50-70%.

Unfortunately there isn’t much research available on the absorption of TG vs EE omega-3 in dogs; however studies have found that in humans, the best absorption seems to occur with fish oil in triglyceride form. [11]


Your Dog Probably Doesn’t Need More Omega-6

How It Works

Omega-6 fatty acids are a strange bunch: they are a mix of pro and anti-inflammatory PUFAs.

The specific “problem acid” is Arachidonic Acid (AA). It can be found in poultry, eggs, meat, and some fish oils.

In response to external conditions such as pollution, smoke, vegetable oils, dietary consumption of linoleic acid (another omega-6, from safflower, primrose, sunflower, hemp, and other plants), arachidonic acid is released from cell membranes. It is then metabolized by various enzymes into substances that can increase inflammation.


EPA can help minimize the effects of AA in the body. The hormones (eicosanoids) made from EPA are much less inflammatory than those from AA. They also reduce the effects by competing with AA for access to the same enzymes. Finally, the actual eicosanoids derived from EPA can counteract the AA ones.

Omega-6 to Omega-3 Ratio

While the specific amount of omega-6 a dog gets from their diet is important, what appears to be most important is the ratio between the amount of omega-6 and omega-3 a dog consumes.

Most dog foods have a high ratio of omega-6 to omega-3, some up to 10:1. A study found that “feeding a diet containing an (n-6):(n-3) fatty acid ratio of 5:1 had a positive, rather than a negative, effect on the immune response of young or geriatric dogs.” [12]

A 2008 study sponsored by a major dog food company found that “… a dietary omega-6:omega-3 fatty acid ratio in the range of 2:1 to 3:1 may be more effective in managing the skin inflammation that is associated with atopy.” [13]

What You Can Do

By giving your dog a high quality omega-3 supplement, you can help balance out the ratio of omega-6 to omega-3 in their diet. This can help support less inflammation in their body, and support overall health and vitality.

Your Dog Should Also Get Vitamin E


“As a free radical scavenger, it protects cells from the potentially damaging effects of toxic oxygen radicals, whose major source is lipid metabolism. The dietary requirement of vitamin E, therefore, is linked to the dietary intake of PUFA, and high fat diets can induce a relative deficiency of vitamin E.”[14]

Translated into English: when your dog ingests more PUFAs (such as omega-3), they are at risk of a vitamin E deficiency. It acts as a powerful antioxidant, protecting the body from free radicals from added dietary fat.

A supplement with vitamin E in it can help prevent the oxidative damage in omega-3 oil. Not only that, but it may also benefit your dog’s skin health, immune system, osteoarthritis, and more.

  • “The findings of this study support the supplementation of vitamin E in dogs with atopic dermatitis.”[15]
  • “… increased dietary levels of vitamin E can improve antioxidant status and modulate oxidative stress in vivo.”[16]
  • “This vitamin also contributes to reducing histological lesions in articular cartilage and decreasing pain associated with the development of OA. Indeed, α-tocopherol appears to modulate a variety of cellular functions that are not necessarily a result of its antioxidant activity.”[17]

You’re Being Misled

When a dog food manufacturer cites that its bag of food has a certain amount of nutrients in it, it’s only right after it’s made. The entire time that it’s shipping and sitting on the shelves, that bag of food may be losing nutrients to oxidation.

By the time your dog finally eats the food, there’s almost certainly not the cited amount of omega-3:

“Levels of PUFA may also be depleted in food after oxidative damage resulting from prolonged storage or in cases in which antioxidants such as vitamin E are included in inadequate amounts.” [18]

Bottom Line

Adding vitamin E directly in your dog’s omega-3 oil can help keep the fish oil fresh for longer, protect against a vitamin E deficiency in your dog, and offer additional overall health benefits.

Not All Vitamin E Is Equal…

Of course, it couldn’t be as simple as saying “Just add more vitamin E to your dog’s diet!”

There just HAD to be eight different types of vitamin E. To keep things simple, we’ll just cover the big differences and considerations.

Synthetic vs Natural

Natural vitamin E is known as “d-alpha-tocopherol.” This is the most biologically active form of vitamin E you can get.

Synthetic vitamin E is known as “dl-alpha-tocopherol.” According to the NIH Office of Dietary Supplements, you need “approximately 50% more IU of synthetic alpha tocopherol” to get the same nutritional effect. Oh, and they are derived from petroleum products.

Mixed Tocopherols?

Don’t be tricked by labels claiming to give your dog a lot of vitamin E, if all you see on the label is “mixed tocopherols.” These are a mixture of the tocopherols family of vitamin E (alpha, beta, gamma, and delta), in varying and usually unconfirmed amounts. This is less desirable since other non-alpha tocopherols have lower levels of biological activity.

This also makes giving your dog the right amount almost impossible, as you can’t know how much they are going to actually absorb from the mixed tocopherols. Additionally, they are rarely provided in nutritionally significant amounts.

GMO vs Non-GMO

Vitamin E can be derived from a number of different sources. It can be derived from soybean, corn, and wheat. These sources are typically from GMO material. There’s some alternatives, however they’re typically more expensive and manufacturers want to minimize expense so they’ll opt for the GMO product.

Just like with the wild-caught versus farmed fish factor, if a brand doesn’t clearly state their product is non-GMO, then it’s probably because they can’t.



It's important to know the different factors that go into a quality fish oil supplement for your dog. There's a lot of noise out there about different products, and we hope this post has helped to clear some of it up.

If you have any questions or comments, please call us toll-free at 1-800-745-0188, or send them to hello@bncpet.com - we love chatting with fellow pet lovers!

We’ve made an attempt to provide as many references as possible for dog parents to do their own research. We offer a non-GMO, wild-caught fish oil supplement for dogs, with natural vitamin E and a pump.

If you found this article helpful, please use the buttons on the side and bottom of the page to share it with another dog parent that might find it interesting!


Suggested Reads:

Natural Versus Synthetic: Why Going Natural May Be Better

Ways to Tell Your Dog’s Coat is Not Up to Snuff

Diet and Nutrition for Your Dog: What is Essential?


[1] Watson (1998) J. Nutr. December 1, 1998 vol. 128 no. 12 2783S-2789S

[2] Logas, D. (1995) Systemic nonsteroidal therapy for pruritus: the North American experience. Proceedings of 19th WALTHAM/OSU Symposium Dermatology, pp. 32–36.

[3] LOGAS, D. and KUNKLE, G. A. (1994), Double-blinded Crossover Study with Marine Oil Supplementation Containing High-dose icosapentaenoic Acid for the Treatment of Canine Pruritic Skin Disease. Veterinary Dermatology, 5: 99–104. doi: 10.1111/j.1365-3164.1994.tb00020.x

[4] Slupe, J.L., Freeman, L.M. and Rush, J.E. (2008), Association of Body Weight and Body Condition with Survival in Dogs with Heart Failure. Journal of Veterinary Internal Medicine, 22: 561–565. doi: 10.1111/j.1939-1676.2008.0071.x

[5] Heinemann KM1, Bauer JE. (2006) Docosahexaenoic acid and neurologic development in animals. J Am Vet Med Assoc. 2006 Mar 1;228(5):700-5, 655.

[6] Kelley R., Lepine A., Morgan D. (2004) Improving Puppy Trainability through Nutrition. Proceedings, Preconf Workshop 6th int, Soc Study Fatty Acids Lipids Cong 2004: 51

[7] Roush J.K, Dodd E.C., et al (2010), Multicenter veterinary practice assessment of the effects of omega-3 fatty acids on f youosteoarthritis in dogs JAVMA, Vol 236, No. 1

[8] LeBlanc CJ1, Horohov DW, Bauer JE, Hosgood G, Mauldin GE (2008) Effects of dietary supplementation with fish oil on in vivo production of inflammatory mediators in clinically normal dogs. Am J Vet Res. 2008 Apr;69(4):486-93. doi: 10.2460/ajvr.69.4.486.

[9] Bauer, J John E.. (2008). Essential fatty acid metabolism in dogs and cats. Revista Brasileira de Zootecnia, 37(spe), 20-27. Retrieved June 12, 2015, from http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982008001300004&lng=en&tlng=en. 10.1590/S1516-35982008001300004

[10] Marjorie L. Chandler, DVM, MS “Top 5 Therapeutic Uses of Omega-3 Fatty Acids”

[11] Martin, D., Nieto-Fuentes, J. A., Señoráns, F. J., Reglero, G. and Soler-Rivas, C. (2010), Intestinal digestion of fish oils and ω-3 concentrates under in vitro conditions. Eur. J. Lipid Sci. Technol., 112: 1315–1322. doi: 10.1002/ejlt.201000329

[12] Kearns RJ, Hayek MG, et al (1999) Effect of age, breed and dietary omega-6 (n-6): omega-3 (n-3) fatty acid ratio on immune function, eicosanoid production, and lipid peroxidation in young and aged dogs. Vet Immunol Immunopathol. 1999 Aug 2;69(2-4):165-83.

[13] Hoffman LA, Jeromin AM, Daristotle L (2008) Omega-6:omega-3 fatty acid ratio affects the clinical signs of atopy.

[14] Watson, TDG. Diet and Skin Disease in Dogs and Cats J. Nutr. 1998 vol. 128 no. 12 2783S-2789S

[15] Plevnik Kapun A, Salobir J, et al (2014) Vitamin E supplementation in canine atopic dermatitis: improvement of clinical signs and effects on oxidative stress markers. Vet Rec. 2014 Dec 6;175(22):560. doi: 10.1136/vr.102547. Epub 2014 Sep 9.

[16] Jewell DE, Toll PW, et al (2000) Effect of Increasing Dietary Antioxidants on Concentrations of Vitamin E and Total Alkenals in Serum of Dogs and Cats. Veterinary Therapeutics • Vol. 1, No. 4 Fall

[17] Rhouma M, Warrak AOE, et al (2013) Anti-inflammatory response of dietary vitamin E and its effects on pain and joint structures during early stages of surgically induced osteoarthritis in dogs. Can J Vet Res. 2013 Jul; 77(3): 191–198.