The 4 Best Fish Oil Supplements For Dogs, According To Vets

These supplements can really help.

fish oil for dogs

If your pup is having issues with his skin, coat or joints, you might be looking for solutions to help him get back in good health.

Fish oil is a supplement that can help dogs suffering from arthritis, allergies and so much more, and it can even help prevent some of these problems from happening in the first place.

While fish oil won’t be perfect for every dog, it can definitely make a huge difference to those pups who it does work on.

We spoke with several veterinarians to find out what fish oil for dogs is, how fish oil can benefit our pups and what their favorite fish oil brands are.

What is fish oil?

Fish oil is a natural oil found in certain types of fish and is often used as a supplement in both dog and human medicine.

“Fish oil is derived from the tissue of cold-water oily fish, including salmon, herring, mackerel, anchovies and sardines,” Dr. Michelle Burch, a veterinarian from Safe Hounds Pet Insurance, told The Dodo.

“It is renowned in the human medicine and veterinary world alike for its health benefits,” Dr. Linda Simon, a veterinary consultant with FiveBarks, told The Dodo. “Indeed, many owners supplement their dogs with fish oil from an early age.”

A huge reason why fish oil is so healthy is because of its high levels of fatty acids.

“It is a particularly rich source of polyunsaturated fatty acids, which have a number of therapeutic and wellness qualities,” Dr. David Haworth, a veterinary advisor for Well Groomed Pets, told The Dodo.

The fatty acids that are in fish oil are eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Both fall into the omega-3 class of oils that have “been isolated to show anti-inflammatory activities,” Dr. Haworth said.

Is fish oil good for dogs?

There are a ton of ways that fish oil can benefit both healthy dogs and those who have certain underlying conditions.

“While most dogs will benefit from adding fish oils to their meals, some need them more than others,” Dr. Simon said. “Those with pre-existing medical issues including atopic dermatitis, dry skin, cardiac disease and arthritis will benefit the most. However, all breeds who are genetically prone to these conditions should be considered as candidates for fish oil supplementation.”

Here are just some of the benefits of fish oil for dogs:

Joint health

Fish oil is an ideal supplement for dogs who suffer from joint issues, like arthritis.

“Supplementing fish oil in your dog's daily diet will decrease symptoms of osteoarthritis with the anti-inflammatory effects of omega-3 fatty acids,” Dr. Burch said.

Veterinarians also prescribe fish oil to help treat a wide variety of other joint issues as well as to support overall joint health. “It also reduces inflammation within joints and can [be] part of the treatment plan for canine arthritis and other joint diseases,” Dr. Simon said.

Skin and coat health

According to Dr. Haworth, fish oil was “originally given as a supplement to help the coat look glossier,” before people realized there were a ton of other health benefits, too.

“Fish oil has been proven to promote a healthy skin and coat, strengthening the skin barrier and locking moisture inside,” Dr. Simon said.

Fish oil can be especially beneficial for dogs suffering from itchy skin due to allergies.

“Fish oil will help reduce symptoms of allergic skin disease causing itching, dry and flaking skin,” Dr. Burch said.

Cognitive function

Fish oil can also be used to help keep your dog’s brain sharp, which is especially important for senior pups.

“In older dogs, supplementation can help improve cognitive function and slow the progression of dysfunction,” Dr. Burch said.

Puppies, too, can benefit from fish oil since it can help their brains and eyes grow.

“DHA is especially important for brain and eye development in puppies,” Dr. Simon said. “Amazingly, studies have even shown that those puppies fed DHA-high diets were easier to train, suggesting they are more intelligent.”

Heart health

“Heart disease patients also benefited from fish oil supplementations with improved survival times and reduced muscle loss secondary to the disease,” Dr. Burch said.

That’s because the fatty acids in fish oil for dogs have amazing anti-inflammatory effects on the heart.

“Omega-3s may reduce cardiovascular disease thanks to their potential ability to prevent irregular heartbeats and to reduce cardiac inflammation,” Dr. Simon said.

Kidney support

Your pup’s kidneys are another system that can benefit from fish oil supplementation.

“Dogs diagnosed with kidney disease can significantly decrease the disease's advancement with fish oil supplementation,” Dr. Burch said.

How to find the best fish oil for dogs

Not all fish oils are created equal, so you should know what to look for in order to find the best one for your pup’s needs.

“There is a wide range of quality in pet nutritional supplements, and fish oil is no exception, so owners need to do their homework and not trust that all supplements are the same,” Dr. Haworth said.

Check the label for EPA and DHA

The most important thing you should look for, according to Dr. Haworth, is that the product is labeled appropriately.

“Most importantly, make sure the fish oil product clearly states how much DHA and EHA is in the bottle,” Dr. Haworth said. “Medical dosing of fish oil (for arthritis, for example) is based on the combined amount of these two molecules, so if you don't know how much is in there, there is no way to accurately dose it.”

If your pup is being prescribed fish oil for a specific condition, your veterinarian will likely recommend a specific dosage of EPA and DHA based on your pup’s needs, so it’s important that you check the label to make sure you’re getting the right amounts of those fatty acids.

If your pup’s healthy, and you’re interested in using fish oil preventatively, you can ask your vet what dosage of EPA and DHA they recommend.

“Read the label to ensure you are supplementing your dog's needs appropriately,” Dr. Burch said. “Fish oil supplements can contain other types of omega-3 fatty acids which are not EPA or DHA, especially if using a human-grade product. If your veterinarian recommends your dog taking 1,000 milligrams once a day, but the supplementation product you are using has 300 milligrams of EPA and DHA, then you are underdosing your pet.”

“In general, you should choose products that are higher in EPA and DHA,” Dr. Simon added.

Look for proof of quality control

You should also check that the fish oil you choose has a quality seal from the National Animal Supplement Council (NASC). “Look for quality control certification by accrediting agencies, and when in doubt, I tend to go with a larger brand since they have more to lose if they are making false claims,” Dr. Haworth said.

Ethyl ester oil vs. triglyceride oil

Fish oil can come in two forms: ethyl ester oil and triglyceride oil. Triglyceride oil is a fat from fish oil that’s in its purest form, while ethyl ester oil comes from fish oil that goes through a process to make the fatty acids more concentrated.

“I recommend purchasing fish oil which is an ethyl ester oil,” Dr. Burch said. “Ethyl ester oils have been distilled to remove impurities while containing a high concentration of EPA and DHA. Products that are natural triglyceride oil may contain contaminants that can be harmful to your dog.”

“I also recommend avoiding synthetic triglyceride oil as the oil is laboratory made and absorbs the least out of the three options,” Dr. Burch said. (Synthetic triglycerides are created when ethyl ester oil is converted back to triglyceride oil.)

Wild-caught vs. farm-raised

Wild-caught fish are more environmentally friendly than farmed fish. “Wild and sustainably caught fish sources are preferred over farm raised,” Dr. Ryan Rucker, a veterinarian with Zesty Paws, told The Dodo.

“From an environmental point of view, steer clear of farmed fish and stick to those that are wild caught,” Dr. Simon said.

Best fish oil for dogs

Here are fish oil supplements for dogs that are made with high-quality ingredients, have high levels of EPA and DHA and have strict quality control standards:

fish oil for dogs

Zesty Paws salmon oil is rich in omega-3 and omega-6 fatty acids and comes from wild-caught Alaskan salmon. It also has the quality seal of approval from the NASC, so you know you’re getting a good product. 

fish oil for dogs

Welactin fish oil is super high quality and comes from small, cold-water fish (which can have less toxins compared to larger fish) that have been caught in the wild. This supplement comes from Nutramax Labs, which promises high-quality ingredients and high standards during the manufacturing process. The best part about Walectin, though, is that it’s flavored with peppermint oil to keep your dog’s breath fresh (and not smelling like fish). 

fish oil for dogs

Dr. Simon recommends this human-grade supplement from Deley Naturals since it’s high in omega-3 fatty acids and low in mercury and other toxins. It also has a super high dose of both EPA and DHA compared to your standard fish oil supplement for dogs.


It’s also designed to be more delicious for your dog. “This liquid supplement has been purified, giving it a more palatable taste and smell,” Dr. Simon said. 

fish oil for dogs

This fish oil comes from Scottish salmon, which are farmed sustainably off the coast of Scotland. It also contains other fatty acids, like omega-6 and omega-9, and has the perfect balance of each, so you won’t have to worry about giving your dog too much or too little of something. 

Fish oil for dogs dosage

The appropriate dosage of fish oil your dog should have per day depends on his condition.

For dogs with heart failure, 40 milligrams per kilogram of body weight of EPA and 25 milligrams per kilogram of body weight of DHA are recommended per day. Most commercial pet foods already contain this amount, so be sure to check the label on your pup’s kibble.

For dogs with arthritis, 310 milligrams of combined EPA and DHA per kilogram of your dog’s body weight daily is the maximum recommended dose, so it’s advised to start with a quarter of the amount and increase the dose slowly.

So if your pup is starting off on fish oil and weighs 40 pounds, you would give him about 1,400 milligrams of combined EPA and DHA a day.

However these are just guidelines, so you should always talk with your veterinarian before putting your dog on a new supplement. Not only can they help you choose the perfect product, but they can also tell you your dog’s ideal dosage.

Side effects of fish oil for dogs

There are some potential side effects of feeding your dog fish oil, though they tend to be pretty minor.

Mostly, you’ll have to deal with bad breath or a smelly pet in general. “I have had a few dogs smell like fish oils [on] their skin after taking them for a while,” Dr. Rucker said. “Not something owners seem to be too thrilled about! But the dogs don’t mind.”

And since fish oil is so high in calories, it’s not really recommended for dogs who need to lose weight. “It is oil, after all, so we need to be especially careful with dogs that are obese,” Dr. Haworth said.

Some dogs are sensitive to fish oil and can develop stomach problems if they have too much.

“Some dogs experience gastrointestinal upset when given fish oil, so it is always smart to slowly add it to the diet and back off if they have any inappetence [aka loss of appetite], vomiting or change in toilet habits or character,” Haworth.

Keep in mind that some dogs could also be allergic to these supplements. “Some dogs can be allergic to fish and will likely react to fish oil in the same way, so always pay close attention when starting a dog on it,” Dr. Haworth said.

You’ll know your dog is having an allergic reaction if he starts showing symptoms like hives, swelling or itching.

Can I give my dog human fish oil?

While your dog will probably be OK if you give him fish oil meant for humans, he’ll be much better off taking a supplement intended for his own species.

“It is safe,” Dr. Rucker said. “I have used human fish oils before for cost reasons, but obviously it’s better to use dog-specific fish oils so we know it is formulated for their specific requirements as well as knowing the accurate dosing and quality.”

If you’re worried your dog might develop joint, heart or other health issues, or if you just want him to be as healthy as possible, talk to your vet about fish oil for dogs to find out if it’s the right supplement for your pet.

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