The Benefits and Precautions of Fish Oil for Dogs

Can dogs eat it

Written By: Angela Jakeson

The Benefits and Precautions of Fish Oil for Dogs
Reading Time: 10 minutes

Fish oil supplements for dogs can provide numerous benefits, including being a good source of omega-3 fatty acids and improving conditions for dogs suffering from arthritis, skin allergies, and renal difficulties.

However, it is important to follow the prescribed dosage to avoid adverse effects such as digestive distress and poisoning.

Learn more about the benefits and potential side effects of fish oil so that you can decide if it is good for your dog.

What Is Fish Oil for Dogs?

A bottle of fish oil for canines splayed on a surface.

Fish oil for dogs is rich in omega-3 polyunsaturated fatty acids. It is extracted from fish. Anchovies, herring, mackerel, salmon, and sardines are the most common sources.

Fish oil for dogs comes in many varieties, but liquid oil and soft gel capsules are the most popular. It is also used as an ingredient in soft chews, treats, tablets, and dog food.

The potency of omega-3 from dog treats is often minimal.

Is Fish Oil Good for Dogs?

Yes, fish oil is good for dogs because it contains high concentrations of healthy fats.

By now you might be wondering: “What are fatty acids found in fish oil?” The fatty acids found in fish oil are omega-3, which comes in 3 different types:

  • Alpha-lipoic acid (ALA)
  • Eicosapentaenoic acid (EPA)
  • Docosahexaenoic acid (DHA)

Out of the three, EPA and DHA are particularly needed by dogs because of their anti-inflammatory effects.

Fish oil for dogs is the most potent source of these omega-3 fatty acids.

Fish Oil vs Flaxseed Oil: Which Is Better?

Flaxseeds and a bowl of flaxseed oil.Apart from fish oil, flaxseed oil also serves as an omega-3 fatty acid supplement. However, it contains large amounts of alpha-linolenic acid (ALA), which needs to be converted first by your dog’s body to form EPA and DHA.

This is where flaxseed oil is at a disadvantage because canines have limited ability to convert ALA to other omega-3 variants.

At best, they can convert 1 to 2% of ALA to EPA. However, when it comes to ALA-DHA conversion, the possibility is slim to none.

In comparison, fish oil is a direct source of DHA and EPA. Therefore, it is convenient to add it to your dog’s diet compared to flaxseed oil.

Why Should I Give My Dog Fish Oil?

fish oil canine health boost infographicFish oil for dogs is popular among dog owners when choosing health supplements for their dogs because of its numerous health benefits.

Here are some of its notable beneficial effects on pooches:

1. Anti-inflammatory

The omega-3 fatty acids EPA and DHA in fish oil supplements for dogs are effective in repressing inflammation. They can offer therapeutic effects on dogs with arthritis.

Research shows that arthritic canines have better mobility when their diet is supplemented with omega-3s.

Fish oil is also thought to relieve symptoms of other inflammatory diseases such as diabetes, skin allergies, inflammatory bowel disease, and certain types of cancer.

2. Alleviates Skin Problems

The anti-inflammatory effects of fish oil for dogs help alleviate allergic skin diseases and other inflammatory dermatological issues.

Omega-3 fatty acids in dogs decrease the production of cytokines, which stimulate inflammation.

A study shows that fish oil for dogs was able to improve the conditions of dogs with itchy skin. Another research suggests that fish oil is more effective in the early stages of skin problems compared to advanced dermatological diseases in dogs.

3. Balances Omega-6 Fatty Acids

Many brands of dog food contain ingredients that are high in omega-6. Dogs might acquire too much of this healthy fat but lack omega-3s.

The imbalance of these nutrients can be damaging to their health. Their bodies need proportionate amounts of these 2 essential fatty acids to function properly.

Supplementing your dog with fish oil will help maintain sufficient levels of omega-3 fats in his body.

4. Hinders the Progression of Kidney Disease

Another benefit of fish oil for dogs is its ability to slow down the development of kidney disease.

It lowers high blood pressure and prevents excessive protein loss in the urine. As a result, this lowers the production of inflammatory compounds, which worsens kidney disease.

Fish oil for dogs also acts as a shield for the kidneys, preventing acute injury to the organ. If your dog has kidney issues, consider supplementing him with fish oil.

5. Promotes Good Cognitive Function

Fish oil for puppies supports fast brain development in young dogs. It is rich in DHA, which is crucial for healthy cognitive function.

A study conducted in 2012 showed that supplementing puppies with DHA enhanced their learning abilities.

This omega-3 fatty acid is also beneficial for geriatric dogs. A study was performed on 142 senior dogs with behavioral abnormalities such as disorientation and changes in sleeping patterns.

After 60 days of eating DHA-supplemented food, they showed significant behavioral improvements.

Potential Adverse Side Effects of Using Fish Oil for Dogs

Scattered fish oil capsules for dogs and a stethoscope.

While fish oil supplements can provide numerous benefits for dogs, you still need to be aware of their potential drawbacks.

By understanding the potential health risks, dog owners can make informed decisions and safely administer fish oil supplements to their dogs for optimal wellness.

High Doses Can Cause Side Effects.

Can fish oil make dogs sick? Yes, fish oil can make dogs sick if given in large amounts. Dog fish oil overdose can lead to a few health issues, most commonly diarrhea, vomiting, and a fishy smell.

Other side effects that may occur due to overdose are:

  • Sleepiness
  • Changes in blood clotting
  • Slow wound healing
  • Oily coat
  • Flaky skin
  • Increased itchiness

Administering fish oil more than the recommended dose over a long period will cause more serious health problems. These include chronic stomach issues, pancreatitis, and abnormal bruising and bleeding.

Thus, if your dog shows early signs of fish oil overdose, discontinue use immediately.

Fish Oil for Dogs May React to Medications.

Fish oil for dogs in a bottle.

Adverse side effects may occur if fish oil is given to a dog taking certain medications. If your dog is prescribed the following drugs, be cautious in giving him fish oil supplements:

  • Anticoagulants
  • Doxorubicin
  • Non-steroidal anti-inflammatory drugs (NSAIDs)

Other prescription and over-the-counter medications may interact with fish oil too. The same applies to vitamins, herbal therapies, and other supplements for dogs.

For your dog’s safety, be sure to consult the vet before administering fish oil if your pooch is taking medications.

Fish Oil for Dogs May Contain Toxins.

The contaminants in the oceans and seas are continuously increasing.

Different varieties of fish tend to accumulate heavy metals and chemicals in their bodies, specifically in their fatty tissues. Unfortunately, these fats are used to create fish oil for dogs.

Heavy metal and toxic chemical contamination in fish oil can weaken the canine immune system and may even induce poisoning.

A relevant question to this topic is: “Is salmon oil good for dogs?” Yes, salmon oil is good for dogs. It is an excellent source of DHA and EPA omega-3 fatty acids.

However, salmon tends to accumulate high quantities of toxins due to biomagnification. This refers to the toxin buildup in an animal as a result of ingesting plants and other animals containing toxins.

To get a clearer picture, let us look into the general food chain of different types of fish in the wild:

Smaller fish eat phytoplankton, which absorbs toxins carried down from the ocean’s surface. Medium-sized fish prey on the smaller ones and in doing so, acquire higher toxin concentrations in their bodies.

Both small and mid-sized fish varieties are hunted down and eaten by larger marine animals such as salmon.

This means these higher-level types of predator fish tend to amass more dangerous levels of toxins than those that belong in the lower food chain.

How about farmed salmon? Are they highly concentrated with toxins like the wild-caught ones? Yes, farmed salmon has elevated quantities of toxins. In fact, it is higher compared to wild-caught salmon.

That’s because farmed salmon has more fats, which is around 14.5 to 34%. In comparison, wild salmon only possesses about 5 to 7% of fat.

Higher fat content means being able to accumulate more toxins, which makes farmed salmon a particularly dangerous source of fish oil.

What Is the Best Fish Oil for Dogs?

Fish oil for dogs on bare hands.

If we are strictly talking about fish oil for dogs with a lower risk of toxic concentrations, the best pick would be those sourced from smaller nonpredatory types of fish.

Since they belong to the bottom of the food chain, they do not accumulate many toxins in their bodies, unlike larger types of fish such as salmon.

Fish oil for dogs sourced from anchovies or sardines fits in this category and is a safer and better choice than salmon oil. Herring and mackerel are cleaner sources of fish oil as well.

How to Choose the Best Fish Oil for Your Dog

Fish-shaped capsules scattered on a surface.

Dietary supplements for dogs, such as fish oil, are not officially regulated. Thus, dog owners must be meticulous when choosing fish oil to ensure that it is of premium quality.

Important notes on fish oil for your dog:

  • Trustworthy companies should have a Certificate of Analysis (COA) for third-party verification. This ensures that their products adhere to international standards for heavy metals and other contaminants.
  • COAs are often posted on the company’s website. If you cannot find it, contact and ask the manufacturer instead.
  • Omega-3 fatty acids in fish oil come in 2 forms: natural triglyceride and synthetic ethyl ester. Avoid the latter as it has less bioavailability to dogs.
  • Some dog owners also note that their dogs experienced flatulence after taking ethyl ester-formulated fish oil.
  • Check the product if it has a natural triglyceride formulation. This information is commonly found on the product label.
  • Fish oil for dogs is susceptible to oxidation, which can easily make it rancid. The COA is useful when it comes to gauging if the fish oil for dogs is fresh.
  • Its anisidine and peroxide values, which are measured by oxidation, help dog owners know the product’s freshness. Fish oil for dogs with less than 5mEq/kg of oxidation is considered fresh.
  • The fish oil should have both DHA and EPA. Take note that each of these omega-3 fats offers different health benefits.
  • If you want to improve your dog’s skin and coat or address dermatological issues, use fish oil for dogs with higher amounts of EPA than DHA.
  • On the other hand, if you are aiming to enhance his cognitive function, opt for fish oil with higher levels of DHA than EPA.
  • Always support sustainability. Do not opt for products using endangered fish as sources. Purchase fish oil for dogs made from fish certified by organizations such as the Global Organization for EPA and DHA Omega-3s (GOED).
  • It would be best to stay away from fish oil made from cod liver. This contains high concentrations of vitamins A and D. These can cause vitamin toxicity in dogs and cats.
  • Pacific fish varieties such as tuna and salmon may contain radioactive particles. This is associated with the Fukushima nuclear power plant disaster, which led to the release of radioactive water into the Pacific Ocean.

How Much Fish Oil Should You Give Your Dog?

Capsules of fish oil for dogs that spell omega 3.

The recommended dose of fish oil for dogs varies by weight. Generally, the advised amount is 75 to 100 mg/kg total EPA/DHA. Irrespective of your dog’s body weight, the daily dose should not exceed 310(kg)¾.

For reference, a dog weighing 22 kilos (50 pounds) will need around 1,700 to 2,270 milligrams (1 to 2 grams) of fish oil per day. The maximum dose must not go over 3,227 milligrams per day.

How to Administer Fish Oil to Dogs

Capsules and liquid fish oil for dogs can be given orally. If this method is difficult to carry out on your dog, try to hide the capsule in a piece of meat, or simply mix it with his dog food.

How to Properly Store Fish Oil

Fish oil for dogs is known for getting rancid quickly if exposed to excessive heat, light, and air.

Buy fish oil in a dark bottle or jar. Then store it in the refrigerator to keep them fresh. As for fish oil gel capsules, place them in the freezer so that they last longer.

If the fish oil starts to have a pungent smell, do not use it anymore and dispose of it properly.

FAQs About Fish Oil for Dogs

Can You Give a Dog Human Fish Oil?

It is not recommended to give your dog human fish oil unless it is labeled 100% pure and consumption grade.

Some products may contain sweeteners and other ingredients not suitable for dogs. So check the ingredients list before making your purchase.

Keep in mind that the dosage of human fish oil capsules differs from those specifically made for dogs. Talk with the vet to find the appropriate human fish oil dosage for your dog.

Is Fish Oil Good for Dogs Every Day?

Generally, fish oil is good for dogs every day provided that they are given the right dosage.

Avoid administering too much of this supplement to keep adverse effects from taking place.

How Fast Does Fish Oil Help Dogs?

Fish oil helps dogs gradually return to good health. It may take time for you to notice a significant improvement in your dog’s condition. However, many dog owners attest that their dogs exhibited positive changes within 3 to 4 weeks.

Should I Refrigerate My Dogs Fish Oil?

Yes, refrigerate your dog’s fish oil right away after use. Do not leave them exposed to sunlight and oxygen as it hastens the oxidation process. This makes the fish oil for dogs get rancid quickly.

You will know if the product is spoiled by doing a taste and smell test. If it has a strong fishy odor and taste, then it is time to throw it away.


Salmon oil capsules for dogs and salmon.

Fish oil is a rich source of powerful anti-inflammatory omega-3 fatty acids for dogs. Giving it to your canine companion as a daily supplement can significantly improve their condition if they have skin allergies, declining cognitive function, kidney issues, or joint problems.

Remember to choose a high-quality fish oil to ensure that your pooch can enjoy its full health benefits.

As a pet parent, there is nothing more important than the health of your dog. If you’re interested in other safe omega-3 supplements for Fido, check out our article on krill oil for dogs.

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