A Vet's Guide to Choosing the Best Fish Oil for Your Dog

Reviewed & Fact-Checked By:
Dr. Elizabeth DeLomba, DVM

When you think of fish oil, the first thing you might think of is a thick, stinky spoonful of cod liver oil. Or the greasy liquid that squeezes out of a can of tuna fish. Yuck!

But, did you know that fish oil is one of the richest and most natural sources of omega fatty acids you can find, and it's an incredible, easy way to add Omega-3 fatty acids to your dog's diet every day?

Let's learn more about why so many vets recommend fish oil as a must-have supplement for healthy, happy dogs.

What are the Benefits of Fish Oil for Dogs?

If you had to pick only one supplement to give your dog, fish oil might be the way to go. It's an incredible superfood for dogs, supporting healthy skin, a lush coat, strong and comfortable joints, brain health and cognition, memory, immune health, digestive health, and so much more.

What makes this fishy gold so healthy?

Omega fatty acids!

Essential omega fatty acids are healthy fats that are absolutely crucial to your dog's diet. There are three main varieties of Omega fatty acids in the dietary world—Omega-3s, Omega-6s, and Omega-9s—with a variety of types within each category. Some Omegas are essential fatty acids for dogs, which means that they can't be made naturally in the body and must be consumed through the diet.

Many commercial dog foods include fish oil and other sources of Omega fatty acids as a healthy boost of nutrients, but the actual levels per serving tend to be relatively low. If you're looking to add Omegas to your dog's diet, supplementing with a quality fish oil is a great choice.

Omega fatty acids are essential anti-inflammatory mediators that have widespread benefits for many key body functions. They are important for structure and support throughout a pet's life. If I had to pick one supplement from which I think the greatest number of pets could benefit, it would be Omega-3 fatty acids."

-Elizabeth DeLomba, DVM, Senior Veterinary Services Consultant

Omega-3 Benefits: Health from the Inside Out

When most people think of fish oil and omegas, they think of Omega-3 fatty acids. They're the most recognized and most-discussed essential fatty acid, and for good reason! These multi-purpose Omegas are well-known to support skin & coat health, brain health, kidney & liver health, heart health, and joint function.

They also act to help promote a healthy inflammatory response to help soothe aches & pains and even ease itchiness and discomfort in dry, irritated skin. Omega-3 fatty acids have also been found to help protect brain health to slow the progression of confusion or poor memory in senior dogs.

EPA & DHA

Two Omega-3 fatty acids deserve a specific highlight:

Eicosapentaenoic acid (EPA)
Docosahexaenoic acid (DHA)

These types of fatty acids are possibly the two most important when you're comparing fish oils, and the two types of Omega-3s that vets look for in the products they recommend.

EPA helps promote healthy, resilient skin, especially in the external layer. It also supports healthy blood flow and strong joints. DHA promotes heart health, muscle health, and has a powerful impact on brain health & cognition.

Omega-6 Benefits: Immunity, Bones, and Metabolism

This is another variety of fatty acid for dogs—like Omega-3s, dogs cannot create Omega-6s in their own body, and they must get enough of it from their diet. Omega-6 fatty acids are important for normal growth & development, supporting a normal inflammatory response, balancing the immune system, supporting bone health and the skeletal system, and promoting healthy metabolism.

Types of Omega-6 fatty acids you may see in dog foods or supplements may include linoleic acid or gamma linolenic acid (GLA). Because Omega-6 acids are so plentiful, especially in common foods that end up in commercial dog foods (corn, safflower, and soy), it's important to make sure you're giving a fish oil that is balanced. Look for a higher amount of Omega-3 fatty acids than Omega-6 fatty acids.

Omega-9 Benefits: A Nice to Have

Omega-9 fatty acids are not considered an essential fatty acid for dogs, since your pup can naturally synthesize this nutrient in their body. Omega-9 fatty acids are often naturally found in the same foods & ingredients that offer Omega-3s and Omega-6s, so you'll find them in many fish oil supplements!

In humans, Omega-9 fatty acids are most often used to support healthy cholesterol levels to maintain heart health & function. However, cholesterol levels are rarely an issue in dogs, so the major benefits of Omega-9s don't typically impact our pets. However, certain breeds may be predisposed to issues with cholesterol, so if you have any concerns, always ask your vet!

Fish Oil vs. Alternatives: What’s the Difference?

Omega fatty acids can be found naturally in a number of foods, including:

Fish like salmon, pollock, anchovies, and sardines
Crustaceans like krill and crab
Shellfish like green-lipped mussel
Nuts like walnuts
Seeds like flax, chia, and hemp
Marine algae like seaweed

Fish oil generally offers higher levels of EPA and DHA Omega-3 fatty acids than plant, nut, or seed oils. Plant-based sources are typically better sources of ALA and Linoleic Acid.

Sources from fish or krill also tend to be more easily absorbed than plant-based fatty acids, making them not just a more effective method of adding omega fatty acids to your dog's diet, but likely a more affordable option, too.

How to Choose the Best Fish Oil for Your Dog

With so many options available, it can be hard to know which fish oil is right for your unique dog.

Fortunately, we have some suggestions to help you get started! Find the best fish oil to use by concern, age, or even budget:

Best Fish Oil for Skin & Coat

While fish oil in general is great for skin & coat health, parents who are looking for targeted support should look for a targeted solution developed specifically to support strong, healthy skin and a lush, glossy coat.

Our Skin & Coat Oil is made with added biotin, Vitamin E, and Vitamin C to help boost the effects of the natural Omega-3 fatty acids from fish, flax, and chia oil. It's a great option for dogs with dry, itchy skin or brittle, weak coats.

Best Fish Oil for Joint Support

When looking for a fish oil to support joint health & comfort, make sure you're buying a formula with higher levels of Omega-3s than Omega-6s for optimal balance. This can help support a healthy inflammatory response throughout the body! Choose our Wild Alaskan Salmon Oil or Arctic Omega Oil (coming soon!) for the highest levels of Omega-3 support.

And for powerful joint health protection, pair a daily fish oil with either our Hip & Joint Chews or Liquid Glucosamine Hip & Joint Oil for well-rounded support.

Best Fish Oil for Puppies & Brain Health

DHA, an essential Omega-3 fatty acid, is believed to play a major role in the development of brain and cognitive health in growing puppies. Our new Arctic Omega Oil is made with 1.5x the DHA of our classic Wild Alaskan Salmon Oil, making it a great option for puppy parents who want the best for their little ankle-biter.

To help maximize that growing mind, pair fish oil with Dog Probiotics to promote a healthy microbiome and support the gut-brain connection.

Best Fish Oil for Senior Dogs

Our frosty-faced seniors deserve the absolute best support during their golden years, and fish oil can play a major part in that! Omega-3 fatty acids help support comfortable joints, healthy inflammatory response, muscle maintenance, brain health, memory, and so much more! Our Senior Support Fish Oil blends pollock & salmon oil with added Vitamin A, Vitamin D, and turmeric extract to help your senior live comfortably and confidently.

Pair with Senior Support Chews to add even more support for cognition, heart function, and vision. Science-backed ingredients like Lion's Mane mushroom, Ashwagandha, CoQ10, and Lutein complement the balanced Omega-3 content of our Senior Support Oil.

Best Fish Oil for Immunity & Overall Wellness

For overall wellness, there's nothing better than our best-selling Wild Alaskan Salmon Oil. This tried-and-true formula helps to support immune health in multiple ways! Omega-3 fatty acids have been shown to help strengthen white blood cells to support a healthy and strong immune response.

Omega-3s also support a healthy inflammatory response throughout the body, which not only helps take some pressure off the immune system, but supports general wellness from nose to tail.

Pair with Multivitamin Chews or delicious Super Greens Granules to help support your pup's overall health and wellness every day!

Best Fish Oil for Pet Parents on a Budget

If you want to support your pup's skin, immune system, joints, heart, and more—but you have to be thoughtful about every dollar—our Ultra Omega Oil might be the perfect solution. It's our most affordable fish oil formula and is packed with Omega-3s and 6s from Wild Alaskan Pollock Oil, Atlantic Salmon Oil, and Flaxseed Oil. With over 2000 mg of total Omega fatty acids per 4ml serving, it's a great choice for budget-conscious shoppers.

How to Identity High-Quality Fish Oils

Now that you know why fish oil is such an important addition to your dog's diet, let's talk about how to find the right fish oil: a high-quality, third-party-tested, origin-verified fish oil made with the best fish on the planet.

Searching "fish oil for dogs" will give you hundreds (or, it feels like, thousands) of options. Liquid, capsules, chews, even dehydrated & powdered fish oil—you can find omega supplements in every type of format and flavor, sourced from every type of ingredient you can imagine. But, if you want to make sure you're getting your money's worth, find a fish oil that meets high standards!

Fish Oil Types & Blends

Fish oil supplements may be made from any type or combination of fish sources—some focus on a single fish while others use a blend of fish oils to make a more robust mixture. Others will blend oils from fish, seeds, algae, or drupes (coconuts).

Creating a formula from a blend of fish oils may help to better balance the Omega fatty acid profile, improve palatability or texture of the final product, or reduce the price point to make the product more affordable to pet parents on a budget.

Transparency & Sourcing

No matter what ingredients end up in a formula, being able to trust exactly what's in your bottle is important. Every Natural Dog Company fish oil blend is made to the highest standards—we only make products that we'll give to our own pups!

ORIVO Verification

Natural Dog Company has multiple products that are proudly ORIVO Verified. This means that our fish oil is fully traceable, clean, and verified by third-party experts.

ORVIO was launched in 2014 by two Norwegian scientists to bring clarity, consistency, and accountability to the Omega-3 fish oil market. They developed technology that could trace marine oils back to the exact species and geographical location—for the first time, delivering a concrete way to test origin claims.

To see details about your fish oil, you can visit ORIVO's website and plug in the number you see on the label near the ORIVO seal.

NASC Quality Seal

All Natural Dog Company supplements and fish oils proudly carry the NASC Quality Seal, which identifies specific brands that are committed to quality and continuous improvement in pet supplements.

That seal means that we've met strict quality control and production standards, had our ingredients reviewed by the NASC Scientific Advisory Committee, and continue to push for improvement in all that we do.

Can I Give My Dog Human Fish Oil?

The safest option is always to give pet-friendly fish oils that are specifically developed for dogs. While there may be human fish oil supplements that are safe for dogs, it's generally not recommended; these capsules or liquids may contain added flavors, dyes, chemicals, or ingredients that are inappropriate or even dangerous for your pup.

Cod liver oil, while well-known as a source of omegas, may contain dangerously high levels of Vitamins A or D, so that's best to avoid as well, unless a product is specifically recommended by your vet.

How to Give Fish Oil if Liquid Supplements Aren't an Option

Liquid fish oil isn't an option for some people—we get it! Even the best, freshest, highest-quality fish oils are... let's just say, pungent.

Whether you struggle to add liquid fish oil into your dog's supplement routine because of personal preference (you or your pup), sensory issues or high sensitivity to smells, or any other reason, there are great alternatives to pure liquid oils!

Soft chews made with fish oil offer many of the same benefits but mix the oil directly into the batter with other healthy ingredients your dog will love! This can help remove many of the sensory or usage issues that may be a challenge for pet parents.

Skin & Coat Chews

Natural Dog Company Skin & Coat Chews are made with many of the same active, beneficial ingredients you'll find in our Skin & Coat Oil, including salmon oil, Vitamin E, and Biotin. These are mixed with real fish, brown flaxseed powder, ground chickpeas, and coconut oil to create a delicious, chewy texture that dogs love.

Soft, chewy texture dogs love
Slightly lower total Omega-3s vs. Skin & Coat Oil
Made with Coconut Oil for added flavor and skin support

Wild Alaskan Salmon Oil Chews

Wild Alaskan Salmon Oil Chews bring all the goodness of our best-selling Salmon Oil blend to a travel-friendly, treat-like format. It's packed with fish oil and made with gluten-free flour for a gut-friendly formula you can really feel good about!

Soft, chewy texture dogs love
Slightly lower total Omega-3s vs. Wild Alaskan Salmon Oil
All the benefits, none of the mess

Comparing Natural Dog Company Omega Supplements

Featured Ingredients	Best For	Total Omega-3*	Total Omega-6*	Main Omega Sources	Additional Key Nutrients	Format
Skin & Coat Oil	Supporting skin health & coat shine	320 mg	50 mg	Fish Oil, Flax Oil, Chia Oil	Biotin, Vitamin E, Vitamin C	Oil
Ultra Omega Oil	Everyday support	615 mg	148 mg	Fish Oil, Flaxseed Oil	None	Oil
Wild Alaskan Salmon Oil	Advanced support; joint health	385 mg	50 mg	Fish Oil	Vitamin A, Vitamin D	Oil
Arctic Omega Oil	Maximum support; cognition; joint health; antioxidants	385 mg	120 mg	Fish Oil, Krill Oil, Algal Oil	Astaxanthin, Vitamin A, Vitamin D	Oil
Senior Support Fish Oil	Cognition; inflammation; healthy aging	285 mg	220 mg	Fish Oil, Borage Seed Oil	Turmeric Extract, Vitamin A, Vitamin D	Oil
Skin & Coat Chews	Supporting skin health & coat shine	120 mg	200 mg	Fish Oil, Flaxseed Oil, Coconut Oil	Biotin, Vitamin E	Soft Chew
Wild Alaskan Salmon Oil Chews	Advanced support	315 mg	45 mg	Fish Oil	None	Soft Chew

*Amounts per pump (2ml) or per chew (3g)

Are There Side Effects to Fish Oil for Dogs?

One common side effect of fish oil? Fish breath! Some pet parents report a pungent, fishy odor coming from their dog's mouth after eating meals. One possible way to avoid this is by giving Dental Powder daily to freshen their breath and help clean their teeth.

The rich consistency and high fat content of fish oil may cause nausea, bouts of diarrhea, or acid reflux in dogs, particularly if you're giving large amounts daily or your pup has a sensitive stomach.

If your dog is sensitive to diet changes or new foods, we recommend adding only a tiny bit of oil for the first few days to help their system adjust. Monitor their health and comfort as needed as you gradually increase to the full recommended dose. Sensitive dogs may require a half-dose of fish oil, or splitting doses into AM & PM, to help them feel their best!

While fish oil isn't really a high-calorie item, dogs getting a high amount of fish oil for joint or cognitive support may be at risk of weight gain. This shouldn't be a problem for most fit, healthy dogs, but if your pup is struggling to maintain a healthy weight, you may want to check with your vet about managing their diet.

Giving excessive amounts of fish oil, or trying to give multiple fish oils in combination, increases the likelihood of unwanted side effects, so make sure you're giving the appropriate dosage as recommended by the packaging or by your veterinarian. In cases of extreme over-supplementation of Omega-3 fatty acids, too much fish oil could possibly lead to nutrient excesses and imbalances, poor immune function, and even detrimental effects on wound healing.

In some rare cases, higher daily doses of fish oil may interact with or interrupt other medications or supplements your dog is taking. It's always best to ask your veterinarian before starting anything new, including fish oil or omega supplements!

Dosage and Getting Started

For most dogs, we recommend following the dosage listed on the bottle—this will be appropriate for the majority of dogs, regardless of age or breed!

However, if you're caring for a senior dog, a dog struggling with joint stiffness or seasonal allergies, or a giant breed, your veterinarian may recommend a higher-than-average dose! This will be dependent on your unique dog's age, breed, size, and metabolic body weight (not necessarily their current body weight).

For instance, some joint health experts recommend 100 mg of total EPA/DHA per kg, per day for dogs experiencing routine or disruptive aches and joint stiffness—for a 40-lb dog, that would be 1,820 mg of Omega-3 fatty acids per day!

(Unless directed by your veterinarian, we do not recommend giving more than the recommended dose of pumps per day of any of our fish oil blends, as it may cause digestive upset.)

When Starting a New Fish Oil:

Start Small: Halve the normal daily dose, or split into AM & PM, so your pup's stomach has a chance to get used to the rich, yummy nutrients.
Transition Slowly: If you're already feeding a fish oil and changing to a new formula, it's a good idea to move gradually to the new oil: Give ¼ of the new oil, then ½, then ¾, then move fully to the new formula.
Watch for any GI Upset: While our formulas are made with clean, high-quality ingredients, any change to diet can lead to diarrhea or gas.
Monitor Positive Changes: It can take up to 8 weeks for the maximum effects to show! While some pet parents may see changes sooner, you're likely to start seeing visible results closer to 6-8 weeks of consistent use.

How to Store Fish Oil for Long-Lasting Goodness

For best results, be sure to store Natural Dog Company fish oil in a cool, dark space, like a cabinet or pantry. Though the liquid is stored in an opaque bottle to protect it, it's best to keep out of direct sunlight. Avoid high temperatures or freezing, as this will affect the quality, consistency, flavor, and stability of the oil.

Fish oil is naturally very strong-smelling but should have a normal amount of fishy scent–like popping open a fresh tin of sardines. If the oil in your bottle smells rancid, please contact us and we'll be happy to assist you!

Not sure if your fish oil has expired?

To find the expiration date for your Natural Dog Company fish oil, look for the "BEST BY:" date printed on the label.