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A Vet's Guide to the Risks and Benefits of Feeding Fish to Your Feline Friend

A Vet's Guide to the Risks and Benefits of Feeding Fish to Your Feline Friend

Should cats eat fish? What you need to know.

Fish is a popular ingredient in cat food, and it's no wonder why, as cats find it irresistible. However, as a veterinarian, I must inform cat owners about the potential risks and benefits of feeding fish to their feline friends.

Myths and half myths abound about feeding fish to cats
Many feel that cats were descended from desert-dwelling ancestors and thus would not naturally eat fish. No scientific evidence supports the theory that cats should not eat fish. On the contrary, cats have been attracted to fish since the original fishmongers tossed them a share of their catch. Then, of course, there are goldfish bowls and the universal cat call of the can opener working on the lid of a tuna can. Cue the attention and taste buds of cats everywhere for everything fish! So what is the bottom line...good or bad?

The #1 problem with eating any fish
Fish, especially tuna, can contain high levels of toxins, such as mercury, PCBs, and dioxins. These toxins can cause serious health problems in cats, such as kidney damage and neurological issues. That is why we must choose the fish we feed ourselves and our pets wisely. Unfortunately, pet food tends to contain the dregs of human fish processing, and by-products unfit for human consumption are more likely to end up in pet food. Making your cat food allows you to reserve some fish that is fit to be reserved and add to your cat's food in moderation.

Can eating fish cause hyperthyroidism?

Risk factors for developing hyperthyroidism include:
  • Exposure to toxins is a potential cause as environmental pollutants are higher in the blood of hyperthyroid cats. Substances such as PBDE's and PFAS (toxins found in fish), flame retardants, and other pollutants. It's more likely the problem is toxins in fish and not the fish themselves.
  • Genetics (Siamese, Burmese, Persian, British Shorthair, Abyssinian, Tonkinese) If you have one of these breeds, consider avoiding fish in pet food that will likely be laden with chemicals that can induce cancer in a cat that could be prone.
  • Canned food diet: can you say unfit for human consumption?


    My cat has kidney problems. Can they eat fish?
    Senior cats or cats with kidney disease should avoid fish due to the high mineral content, such as magnesium and phosphorus, in low-quality fish that can lead to kidney problems or urinary tract issues. Commercial cat foods with fish also often contain preservatives that can cause adverse side effects such as altered liver function.
    It's important to note that fish oil from wild-caught fish has beneficial Omega-3 fatty acids that are helpful in the case of renal disease. Studies have shown their beneficial effect of taking them on life expectancy.

    Should cats eat raw fish?
    No. Raw fish contains parasites and potential foodborne illnesses. For example, dogs can get salmon poisoning from eating raw salmon, but cats are resistant to it. This is caused by a parasite found in raw fish, which can be potentially fatal to dogs. Cooking fish destroys parasites, and the risk of foodborne illness is mitigated.

    Can my cat eat tuna fish?
    Of all the types of fish, tuna seems to appeal to cats. Just open a can and watch them come running from parts unknown. However, tuna has high levels of mercury, so it is best to treat only a few flakes of low-sodium tuna. Humans should limit consumption to 4 ounces per week per the USDA.

    Safe Options for Feeding Fish to Cats

    What about fish oil?
    You should add a source of Omega-3's to your cat's diet if you skip feeding fish to your cat. Omega-3 fatty acids are important for neurological health and are naturally anti-inflammatory. They also contain little fish protein.

    Can my Cat Eat Tilapia?
    Tilapia, in moderation, is a healthy source of protein and can complement a poultry diet nicely.

    Can my cat Eat Canned Fish?
    As long as the fish is in water and low in sodium, especially for seniors, it's o.k. I would avoid it in the case of kidney disease.
    • Sardines
    • Mackerel
    • Wild pacific salmon

      Can my cat eat line-caught fish or whitefish?
      Yes! As long as it is cooked and the bones removed.
      • Flounder
      • Halibut
      • Tilapia

        Can cats eat anchovies?
        Anchovies are not a good choice as they are usually heavily salted and contain a lot of oil.

        Can my cat eat shellfish or shrimp?
        Tidbits of cooked and cleaned shellfish and shrimp are o.k. so long as they are not heavily salted or spiced.

        Are allergies to fish common?
        They are not, but cats are more likely to react to all the toxins in the dregs of fish by-products unfit for human consumption that are added to pet food and not fish proteins themselves.

        What does an allergy to fish look like?
        Cats will usually have skin issues as more so than gastrointestinal issues such as vomiting and diarrhea. Symptoms include excessive facial itching, barbering or removing hair on the abdomen, and ear infections. These will often start at an early age; however, it is possible to develop a food allergy to a food that a cat has been eating for years.

        Everything in Moderation!

        In conclusion, feeding fish to cats can be a healthy and nutritious addition to their diet. However, presenting it in moderation and adequately cooked will avoid health complications with cats. By avoiding raw fish, investing in high-quality oily fishes with healthy Omega-3 fatty acids, and removing bones before cooking, you can safely provide your feline friend with the many benefits of fish.

        Hi! I'm Dr, Dody, DVM.

        Passionate about animal welfare, I dedicated my life to helping animals from a young age. After years of traditional medicine, I discovered a lack of dietary options for optimal health. Combining my experience in both traditional and holistic care, I created Holistic Vet Blend® to empower consumers in choosing healthy ingredients and provide essential nutrients. As a seasoned veterinarian and thought leader, I advocate for a personalized approach to improve pets' lives. We support you in curating your pet's bowl, monitoring their progress, and offering the latest recommendations as their needs change.

        Together, let's redefine pet care with love and attention.