Fish Oil for Cats: A Word of Caution

By Chelsea Hunt-Rivera / December 4, 2018
fish oil for cats

One of the most commonly added dietary supplements is none other than fish oil. A quick Google search is typically all that’s needed to make many pet owners run out for a bottle of the dietary supplement not only for themselves but for their beloved four-legged friends as well. From promoting skin health to preventing cancer development, fish oil is truly making a name. In fact, the use of fish oil has become so common that it is now considered to be a conventional or “mainstream” medication rather than an alternative method of treatment.  However, it is imperative that cat owners understand that the benefits of fish oil don’t come without potential risks.

In this article, we’ll cover everything you should know about fish oil for cats before you decide to give it to your feline friend. While fish oil does have its health advantages, there are possible adverse reactions that cat owners must recognize. Let’s get started!

fish oil for cats

What is Fish Oil

As its name implies, fish oil is the oil derived from the tissues of a number of different fish. The oil supplements contain Omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Both Omega-3 fatty acids are naturally produced in a limited capacity and are poorly synthesized, especially in cats. Understanding this information causes many cat owners to wonder whether an additional fish oil supplement would benefit their feline.

Interestingly enough, while the EPA and DHA fatty acids in fish oil supplements come directly from the fish, the fish receive the fatty acids from algae. Sadly, as many fish populations in our oceans continue to decline, many believe that algae will likely become the dominant source of omega-3 fatty acids for both people and our animals.

Presently, fish oil supplements are typically derived from salmon, sardines, mackerel, herring, albacore tuna, trout, black cod, and anchovies.

Fish Oil Benefits

Years of studies prove that fish oil can not only benefit people, but cats and dogs as well. In fact, experts at Utrecht University in the Netherlands proved that cats absorb the fatty acids of fish oil, instead of the supplement simply passing through their body. The study also showed that the fish oil didn’t cause a spike in the cats’ cholesterol levels.

With that said, if your cat is currently being fed a well-balanced, species-appropriate diet, it is unlikely that they have a fatty acid deficiency, as most cat food is comprised of the very fish we previously mentioned. We don’t want to try to convince our readers that fish oil is a miracle supplement that will 100% change your cat’s life, particularly if they are young adults and in good health. However, for older cats, implementing fish oil has shown to have many benefits worth discussing.

EPA: A Powerful Anti-Inflammatory

For starters, the EPA fatty acid in fish oil proves to have incredibly powerful anti-inflammatory properties. It can help reduce and manage inflammation in just about any part of the cat’s body that you can imagine. The anti-inflammation abilities of EPA can, therefore, promote heart health, kidney function, overall skin condition, and prevent joint degeneration. Let’s discuss a few of these advantages further.

Skin Irritation Relief

Most often, allergies in people lead to sneezing, coughing, and red eyes. In cats, allergies commonly cause dry, itchy, and irritated skin. Both cases, inflammation as to blame. Because of its anti-inflammatory properties, many cat owners have seen a reduction in allergy-related skin irritation once implementing a fish oil supplement into their feline’s diet. Additionally, many pet owners report that fish oil supplements have reduced the number and severity of hot spots on their pets. Hot spots on dogs and cats are no fun for anyone. The fact that a simple supplement could help avoid the condition is something worth considering for many pet owners.

Healthier Coat & Fewer Hairballs

Many cat owners have found that implementing a fish oil supplement has improved their feline’s coat quality. Comparable to other fat supplements, fish oil promotes a shiny coat as well as a reduction in shedding. A decrease in the amount of hair shed also means significantly less hair that is ingested through self-grooming. Therefore, many cat owners have found that by implementing a fish oil supplement, their cat experiences fewer hairballs. Additionally, fish oil can help reduce and manage inflammation in the digestive tract. If your cat has thick fur and experiences hairballs and subsequent gastrointestinal upset, we highly recommend talking to your veterinarian about whether a fish oil supplement may be able to help.

fish oil for cats will improve fur

DHA: Brain and Eye Development

DHA, one of the fatty acids found in fish oil, promotes brain and eye development in kittens and puppies alike. Therefore, giving your pregnant or nursing dog a fish oil supplement can, in turn, greatly benefit their babies.

Slowing Cancer Growth

Many experts suggest that fish oil may be a key component in slowing tumor and cancer growth. This is, once again, due to its powerful anti-inflammatory properties. Additionally, the fatty acid DHA has the ability to shrink tumors by promoting cell differentiation. In other words, DHA limits the number of times that cancer cells can divide, therefore, slowing its growth and ability to spread. Of course, we are by no means suggesting that fish oil will cure your cat’s cancer. We are, however, saying that more and more studies are proving that fish oil supplements may be able to make a significant difference. As additional research emerges, we hope that more cat owners will be able to prevent their feline’s disease through the use of an all natural supplement such as fish oil.

Joint Health

Fish oil supplements are also known for easing arthritic joint pain and inflammation. Again, this is due to its incredibly anti-inflammatory properties. Cats can experience joint issues for a number of reasons from injury to disease to the normal aging process. My veterinarians recommend implementing a fish oil supplement to promote overall joint health and prevent further inflammation from developing.

Fish Oil for Aging Cats

Numerous studies prove the benefits of fish oil supplements for aging cats. The supplement has shown to prevent brain degeneration and diseases including dementia. Experts recommend combining fish oil, b vitamins, and additional antibiotics in order to thoroughly protect your older kitty’s brain. Furthermore, a study dating back to 1979 showed that fish oil supplements could also protect cats against stroke.

In aging dogs, fish oil proves to help protect against heart attack. Studies are still being conducted to prove if the supplement can benefit cats in the same way.

Inflammatory Bowel Disease in Cats

Finally, inflammatory bowel disease (also known as IBD) is a common ailment diagnosed in felines. It is a condition that results from chronic inflammation and irritation of the stomach or intestines. Studies have found that fish oil supplements can help relieve symptoms of inflammatory bowel disease as well as prevent the condition from worsening.

How Does Fish Oil Work

Both EPA and DHA are fatty acids that play tremendously important roles within the cell membranes of people as well as dogs and cats. EPA and DHA act as signals and alert the body to decrease levels of inflammation. Many pet owners may not realize that inflammation is at the source of nearly every disease imaginable. From allergies to cancer, inflammation is involved. Therefore, EPA and DHA fatty acids are incredibly important for not only reducing present inflammation but also preventing it from spreading and developing in the first place. (This goes for you and your four-legged friends!)

how does fish oil for cats work

Fish Oil Side Effects: Understanding the Risks

Although fish oil certainly can have its health benefits for cats, it also has its potential risks. It is important for cat owners to understand the potential adverse reactions as well as the details regarding specific fish oils before deciding to implement the supplement into their cat’s diet.

Higher Blood Loss

One risk of fish oil is its ability to cause excessive blood loss if the cat experiences an injury, trauma, or has to have surgery. The high EPA and DHA levels cause alterations in platelet function. More specifically, they cause a decrease in platelet activity as well as the body’s ability to form blood clots. Therefore, cats who are given fish oil will experience higher blood loss than those who have normally functioning platelets.

Farm-Raised Salmon

Additionally, the majority of salmon oil comes from farm-raised salmon. This is troubling for a multitude of reasons. First, farm-raised salmon live in overcrowded, heavily polluted pens. They are heavily vaccinated and fed dyes to make them orange in color. They are also constantly fed and surrounded by antifungals, parasiticides, and antibiotics. Research proves that they contain up to ten times more toxins than wild caught fish. Furthermore, oil derived from farm-raised salmon contains substantially less omega 3s and more omega 6s than oil derived from wild caught salmon.

Many cat owners may read the aforementioned information and think to themselves, “no worries, I’ll just buy wild caught salmon oil.” Unfortunately, that doesn’t exactly solve the problem. Many sources of salmon oil that are labeled “Alaskan” and “wild-caught” aren’t actually wild-caught at all. Instead, they are bred and grown in hatcheries only to be released into the oceans and then “wild caught” later on. This causes even more issues as the hatchery-born salmon can carry diseases and parasites that can affect other fish who have not been administered antibiotics.

farm-raised fish oil for cats is unhealthy

Dangers of Cod Liver Oil

There are also dangers of cod liver oil. Cod liver oil often contains high levels of vitamin A and vitamin D which can become toxic in both cats and dogs. Even more worrisome is the fact that there is a loophole in the law that allows non-cod fish to be labeled as cod.

Fillers and Additives

Additionally, with the rise in popularity of fish oil supplements comes a large number of companies mass producing the product. Unfortunately, now many fish oil products are chock full of fillers that increase the levels of omega 6s, which can be harmful to your cat. Most are also processed with harsh chemicals that will ultimately cause much more harm than good. Even more concerning is the fact that it can be extremely difficult to decipher between a company who is mass producing fish oil and a company that is reputable.

Radiation Poisoning

The concern with fish oil doesn’t stop with troubling additives and toxicity. In 2011, a tsunami hit the Fukushima nuclear power plant causing its reactors to melt down. This, in turn, led to radioactive water entering into the Pacific Ocean. Now, an estimated 300 tons of the radioactive water still seeps into the Pacific Ocean. It’s a horrifying thought to consider.

Even scarier for people living in different parts of the world is that the radioactive waters have spread into different oceans. In fact, seven years later, the radioactive waters resulting from the 2011 tsunami are affecting the west coast of North America, affecting a great number of marine life… many of which we continue to eat.

Harmful to the Oceans

Last, but certainly not least, the booming fish oil business is ultimately incredibly dangerous for our oceans. Many people may think that purchasing oil derived from wild caught fish can eliminate most (if all) of the associated negative repercussions. However, this is far from the truth. Stop and consider how the fish are caught. They are gathered up from through a by-product of fisheries with nets. The process is called by-catch. Sadly, there is a great deal of marine life that is caught in the nets including dolphins, whales, and sea turtles. The horrifying truth of the matter is that an estimated 300,000 whales, porpoises, and dolphins are killed each year due to fishery nets. That is a staggering and extremely troubling statistic.

Furthermore, there are many species of fish that are highly desirable for their high levels of omega 3s. Therefore, these species are being caught more quickly than they can reproduce. In many cases, these fish are extremely important for the ocean and therefore the ocean’s ecosystem is suffering without them. For instance, the menhaden fish is responsible for eating algae blooms and keeping the ocean waters clean and full of oxygen. The menhaden fish is also a highly sought after fish for its high levels of omega 3s. In turn, experts have now discovered the development of dead zones due to the lack of oxygen in the oceans.

fish oil for cats can endanger the ocean

Finding the Best Fish Oil Supplement

We understand that some of our readers might feel that the pros of fish oil outweigh the cons when it comes to their feline. If this is the case, it is incredibly important that cat owners make sure that they purchase the best fish oil available.

Nordic Naturals

One company that we have found to be a reputable source of fish oil is Nordic Naturals. The liquid fish oil contains 31% omega fatty acids, including 17% eicosapentaenoic acid which helps cats suffering from kidney disease.

As always, do your homework and consult with your veterinarian regarding companies that you can trust.

Fish Oil Dosage

Ultimately, the appropriate fish oil dosage will depend on your cat’s weight and the ailment that you are trying to relieve and/or prevent. More severe ailments typically require a higher dosage. Again, if you choose to use fish oil, we highly recommend consulting with your holistic veterinarian regarding what dose will benefit your feline’s individual needs. Additionally, make sure your vet is implicitly aware of any pre-existing health conditions that your cat has. Cats with specific medical issues should not take fish oil supplements.

Alternatives to Fish Oil

Due to the potential adverse reactions associated with fish oil, many cat owners find themselves seeking out alternatives that can provide comparable benefits. While these alternatives do exist, they don’t necessarily come without possible consequences. Let’s take a look at the pros and cons of several fish oil alternatives.

Greenlip Mussel Oil

New Zealand greenlip mussels are grown in a controlled environment that has a minimal effect on the environment. Greenlip mussels (also referred to as GLM) contain an impressive 33 fatty acids including omega 3s DHA and EPA.  Additionally, GLM contains an omega 3 called ETA (eicosatetraenoic acid). ETA is not found in any other food source at such a measurable degree. Studies have found that the omega 3 is highly beneficial to heart health and has extremely potent anti-inflammatory properties. Finally, greenlip mussel oil contains significantly less saturated fat and greater levels of mono- and polyunsaturated fats than both fish oil and cod liver oil. When it comes to choosing a fish oil alternative, we highly recommend looking into greeplip mussel oil for your beloved four-legged friend.

Krill Oil

Krill oil is a non-fish alternative option that can provide your feline with beneficial omega 3 fatty acids. Tiny shrimp-like crustaceans, krill are the main food source for many forms of marine life including fish, seals, whales, squid, and birds. While many experts state that it is impossible to over-harvest krill, there is a serious repercussion to its farming. Krill is being harvested in areas in the feeding grounds of the animals that eat them. Because of this, there have been local areas with worrisome depletion of many species including whales, fish, and seabirds.

CBD Oil for Cats

If you want your feline to reap the benefits of a supplement chock full of anti-inflammatory properties without the potential adverse reactions of fish oil, we recommend CBD oil for cats. Derived from the hemp plant,  CBD oil is changing the ways that cat owners can treat and manage their feline’s ailments. As we previously mentioned, nearly every health condition has one major thing in common: inflammation. Luckily, CBD oil contains high levels of anti-inflammatory properties that can alleviate and prevent everything from allergies to arthritis. In fact, CBD oil is so effective that scientists are considering it to be a new drug class for the treatment of chronic pain. The best news? CBD oil has virtually zero side effects. That’s right! Your feline can experience all of the benefits that an anti-inflammatory supplement has to offer without the fear of side effects.

cbd for cats

Coconut Oil for Cats

Coconut oil is a supplement that is often misunderstood. While coconut oil for cats can provide your feline with several benefits, it does not contain omega 3 fatty acids. However, coconut oil can be used both internally and externally to treat a slew of health issues. Click here to read more about all the ways coconut oil can benefit your feline.

Fish Oil for Cats: The Bottom Line

At the end of the day, we know that you want the very best for your beloved feline. We totally understand! At Simple Wag, we are all cat owners and animal lovers. Therefore, we know firsthand that being a cat parent isn’t always easy. When problems arise (and they inevitably do), it is important for cat owners to do their research and choose the best product or medication available. When it comes to fish oil for cats, knowing the risks is imperative. Yes, fish oil can provide your feline with a number of potential benefits. However, these benefits come with a fair share of possible dangers. We highly recommend considering a fish oil alternative. If you’re looking for a supplement with omega 3’s, consider greenlip mussel oil. If you’re simply looking for a powerful anti-inflammatory supplement, look no further than CBD oil.

As always, we recommend consulting with your holistic veterinarian regarding your cat’s individual needs and how a fatty acid supplement may be able to help.


Fish Oil For Cats – The Benefits And How To Serve It

What Is the Best Fish Oil for Cats?

Choosing an Omega-3 Oil for Your Pet



About the author

Chelsea Hunt-Rivera

Chelsea Rivera is a Dedicated Pet Parent who loves to create amazing content for pet owners and is helping change pet wellness as the Head of Content for