Cats have long been portrayed as wholly fish-obsessed and willing to go to great lengths to get themselves some fishy treats.

Cue visuals of cats hungrily eyeballing the family goldfish as it swims about in its bowl.

Cue alley-cat references of felines harassing fish shop owners and oftentimes making off with a head or a tail to the fishmonger's dismay.

And we've all bought into the narrative that cats eat fish and should be fed fishy dishes in perpetuity. But how scientifically accurate is this? Is fish good for cats? And if so, are all types ok? Or are some kinds of fish better than others? Find out!

  1. Can cats eat fish
  2. Raw fish | Fish bones
  3. Fish in commercial cat foods
  4. Microplastics and heavy metals
  5. Common types of fish and seafood | Tuna | Salmon | Sardines | Line fish | Anchovies | Shrimp | Shellfish | Squid and octopus | Seaweed | Goldfish
  6. Benefits of fish oil
  7. Fish allergy in cats | Signs | What to do
  8. Takeaway

Can cats eat fish

Cats most certainly can eat fish. An occasional fishy snack won't be harmful to your cat in most cases, but it isn't a nutritionally complete food source for your cat. It means that while fish will provide your cat with the protein it needs, it is deficient in various minerals and vitamins that your cat needs for a healthy diet. Fish for cats should always be an occasional treat.

So, why do cats like fish? Over time modern domestic cats have come into contact with fish and developed a fascination with them. From their distinct smell and how they move to their glistening scales that play with the light, fish are simply irresistible to cats. Fish for cats is a fascinating, glittering toy that smells peculiarly interesting.

Can cats eat raw fish

cat and raw fish

It's a hard no-no. Raw fish is unsuitable for cats as it contains an enzyme called thiaminase that destroys thiamine which is an essential B vitamin for your cat. If cats have too little thiamine, they might experience some severe health problems.

What's more, raw fish is usually a breeding ground for bacteria which, like in humans, can cause food poisoning in your cat. Take E. coli and salmonella as examples of two hazardous bacteria that can affect felines and humans.

Following the same logic, you might wonder, "can my cat eat sushi?" Actually, no, primarily because of its high raw fish content. But, on the upside, that does mean there's more for you, though.

Can cats eat fish bones

Fishbones are as problematic for your cat as they are for you. The only difference is that you can detect and remove the bones before you swallow, while your cat most likely won't become aware of the fine little spines until they're lodged somewhere in their mouth and digestive tract.

Not only is it painful for cats, but swallowing a fishbone can also result in internal organ damage. And don't forget that fishbones are a choking hazard, so make sure to avoid feeding them to your kitten. After all, they offer no nutritional benefits compared to a yummy slice of cooked and unseasoned fish.

Fish in commercial cat foods

Commercial cat foods that list fish as a key ingredient don't always use the best quality fish. Usually, they contain offcuts and leftovers not suitable for human consumption. It means that, nutritionally, this fish isn't likely to offer your cat any of the benefits that good quality fish might.

This low-quality fish usually contains ground-up bones, guts, and other less-than-appealing fish bits high in minerals such as magnesium and phosphorus. If your cat consumes too much of these minerals, it can cause kidney problems or issues in the urinary tract. If your cat already has kidney problems, they probably should avoid eating fish altogether.

Commercial cat foods are also likely to contain preservatives to extend the fish components' shelf life, which can cause some adverse side effects for your feline, such as altered liver function.

A note on microplastics and heavy metals

A topic of microplastics found in daily foods is not new, with dozens of such news appearing daily. The situation is that it is no different when it comes to fish. In particular, a valid research proves that most fish contain microplastics, mostly as a result of ocean pollution. Besides that, such fish might also test positive for heavy metals like mercury and other toxins that can seriously affect cats and humans.

Because of ocean pollution, most fish also accumulate high content of mercury and other toxins. The higher up in the ocean food chain, the more of these toxins the fish is likely to contain as these toxins are never destroyed and only accumulate up the chain. So, a fish like a tuna, which eats other smaller fish, accumulates higher levels of these metals and toxins and should be eaten less frequently.

Common types of fish and seafood

If you're wondering which types of fish are okay for felines, which ones should only be offered as a rare treat, and which ones to ban completely, take a look at the list below.

Can cats eat tuna

Any cat owner can tell you that simply opening a can of tuna will cause your cat to stage a frenzied campaign to get some at any cost. But is tuna good for cats?

Cats LOVE tuna, but unfortunately, tuna does contain high mercury levels, while a diet that is high in tuna can lead to your cat developing mercury poisoning. As a predatory species that eat other fish, tuna tends to accumulate higher levels of heavy metals and toxins and should not be consumed too frequently.

That said, cats can eat tuna as an occasional treat if it's cooked and not raw. Also, it's advisable not to make tuna a regular menu item in your cat's diet – cats have been known to become so obsessed with tuna that they refuse to eat anything else.

Canned tuna as a rare treat from time to time is probably fine but be aware that canned tuna, in addition to heavy metals, often contains higher sodium and other preservatives.

Tuna in brine is too high in salt, which is not healthy for your cat to consume, whereas tuna in oil should be properly drained to avoid the high-calorie punch that the oily fish and additional oil will provide.

Can cats eat salmon

Salmon is indeed nutritionally decent for cats and contains many vitamins that benefit felines. If you're choosing to feed your cat salmon, make sure it is always cooked but isn't smoked or mixed with any herbs and spices that may upset your cat's stomach. You should avoid canned salmon as it often contains too much salt and preservatives that are bad for your cat.

Avoid commercial cat food that includes salmon. Most salmon used in commercial cat foods is farm-raised, which means the fish are often exposed to high levels of pollutants and toxins. Besides, because the fish are reared in often overcrowded conditions, they're fed antibiotics to limit the spread of disease.

If you're still going to give your cat a salmon treat, do so rarely and cook it yourself. The best options include grilled, poached, and baked salmon without salt and extra spices.

Can cats eat sardines

Sardines or pilchards are an excellent source of Omega-3 fatty acids, vitamin B12, and protein. Practice moderation here, as the high-fat content in these fish potentially causes weight gain, not to mention that these fish may contain heavy metals and toxins.

If you decide to treat your cat to some sardines, make sure to cook them. Avoid smoked sardines, and if you're using canned varieties, always check the labels. Sardines preserved in brine will have a very high sodium content and should be avoided or, at the very least, rinsed before serving.

Those preserved in oil should be thoroughly drained to avoid giving your cat too much high-calorie oil. Whenever possible, go for sardines, which don't contain garlic, onion, and tomato.

Can cats eat line fish

But what about line fish, such as cod, halibut, flounder, hake, and tilapia? All these fish are fine for cats but make sure they're free of bones and don't contain salt and other harmful ingredients. A general rule of thumb is simple: baked, grilled, or boiled white fish without extra salt and seasoning are great for cats.

Pay attention that these fish don't contain any of those healthy fish oils and omegas, so they're not as nutritionally valuable to your cat's diet, but they won't do any harm.

Can cats eat anchovies

cat and anchovies

Anchovies are a great source of healthy unsaturated fats for your cat. Use caution here as these fatty fish can contribute to weight gain, especially if they're preserved in oil. If you bought canned varieties in oil, make sure to drain as much oil as possible. For brined anchovies, rinse off as much of the salt as you can.

Another good thing about anchovies is that they're somewhat lower on the food chain and contain less mercury and other heavy metals from ocean pollution.

Can cats eat shrimp

Shrimp and prawns are generally safe for cats to consume. Shrimp is great as an occasional snack for felines because they combine low calories with high protein content. They are also high in zinc, copper, Omega 3, and vitamin B12. Don't make it a regular habit, though, as shrimp is high in sodium and cholesterol.

The best way to feed shrimp for cats is to cook it without oil, salt, and seasonings. As processed and pre-packaged shrimp or prawns will likely contain salt and other ingredients that may not be beneficial for your kitty, it's best to avoid these as a rule.

A friendly recommendation for those giving fresh shrimp to a cat — remove its digestive tract as it isn't good to eat. Because it contains all the food a shrimp ate before, completely ripping it off is highly advised.

Can cats eat shellfish

People worldwide enjoy shellfish, including clams, scallops, mussels, crabs, oysters, and lobsters. But can they share their meals with cats?

Shellfish are packed with calcium, iron, copper, zinc, and other essential minerals. Being high in protein and low in fat, they can be a decent treat for felines that might appear in your cat's bowl from time to time. As it works with shrimp and fish, make sure shellfish are clean, fresh, and cooked without salt and seasonings.

Can cats eat squid and octopus

Octopus and squid are high in iron, copper, and zinc, making them a great treat to share with your cat. As long as these are fresh, clean, and cooked, they should be okay to give to your cat as an occasional snack. However, keep in mind that both squid and octopus are high in cholesterol.

Can cats eat seaweed

Seaweed a perfectly healthy snack for your cat when offered in moderation. For some felines, tiny bits of seaweed help solve minor digestive issues. Seaweed is also speculated to have a positive effect on your kitty's fur and skin.

As long as it is of high quality and free of any other ingredients (such as salt, garlic, spices, and preservatives), it should be just fine to share with your feline.

Can cats eat goldfish

cat and goldfish

This one's a little different. You wouldn't willingly feed your goldfish to your cat (we hope!), but is it ok if your cat manages to get hold of, and eat, a goldfish?

Technically speaking, your cat should be ok (RIP Bubbles, though), but a small and wriggly fish can pose a choking hazard to cats, so we do advise keeping your cat out of the fishbowl or pond.

If your cat consumes a goldfish, it might be a good idea to get them to a vet. Fish frequently carry bacteria and parasites like tapeworms, which can transmit to your cat. Also, goldfish counts as raw fish, which generally contains thiaminase, a harmful enzyme for felines.

Benefits of fish oil

Oily fish such as tuna, salmon, and sardines are a superb nutritional supplement to your cat's diet. They are rich in healthy fats such as Omega-3 and Omega-6, which are great for your cat's eyesight and heart health. Fish oil is also great for older cats who may have stiff or painful joints, arthritis, and other inflammatory conditions.

Thanks to the wonders of modern science, you're now able to skip the fish altogether and go straight for the oil, where most of the benefits lie. Fish oil supplements are a convenient way to add these healthy fats to your cat’s diet.

While it's tempting to rush out to get your paws on one of the many supplements for cats, it may be worth chatting with your veterinarian first. They can advise on the best quality supplements to use, as well as the correct dose to use for your cat.

Fish allergy in cats

Yes, you read that right. Your cat can be allergic to fish. While it's not very common for a cat to develop an allergy to fish, the number of fish allergy cases among cats is rising. Make sure to distinguish between allergy and intolerance, with the former relating to the immune system and the latter to a gastrointestinal response.

Unlike human food allergies, cat ones can be hard to diagnose as there aren't any reliable allergy-specific tests that can be used. Instead, identifying a food allergy is a lengthy trial and error process, usually followed by an elimination diet. Except for fish and seafood, felines may also be allergic to beef, dairy, and even eggs.

Signs of fish allergy in cats

Typically, food allergies show up as skin conditions like redness and itching, alongside hair loss that results from the scratching. Excessive shedding, frequent hairballs, and persistent ear infections can also sign a food allergy. Acute moist dermatitis and crusty papules are also possible.

In some felines, food allergies cause gastrointestinal issues, including vomiting and diarrhea, in addition to the skin problems mentioned above. Very rarely, your cat may develop respiratory problems. If you spot any of these signs, contact your vet immediately.

What to do if you think your cat has a food allergy

Always consult your vet first. They will be able to rule out any other medical conditions. Never try to treat a suspected allergy by yourself. Be sure to closely monitor any changes to your cat's diet to ensure that your kitten is still getting all the nutrition that they need.

In the absence of any other conditions that could explain the symptoms, your vet will likely require you to begin an exclusion diet and close monitoring of your cat's symptoms to help identify the particular allergen causing the problem.

Takeaway

  • Cats are not natural fish consumers, but fish can be a healthy and nutritious addition to an already balanced diet. When cats are given fish as an occasional treat, your cat will most likely be fine unless they are allergic to a particular fish or seafood.

  • Always remember to give your cat the best quality fish you can. Aim for fresh cuts instead of pre-packaged, ready-to-eat, or canned varieties that contain salt, preservatives, and other potentially harmful ingredients. Boneless or deboned fish is preferable.

  • Never give raw fish to your cat. It can cause severe depletion of essential vitamins.

  • Fish that you intend to feed to your cat should never be cooked in garlic or spices or too much oil. Boiled, baked, or grilled fish works best for your cat.

  • Oily fish like tuna and sardines offer more significant nutritional benefits to your cat in the form of healthy fats than white fish such as flounder or hake.

  • As always, consult your veterinarian if you have any concerns about your cat's diet. Don't attempt to treat any suspected allergies yourself, and if you wish to supplement your cat's diet, always chat to your vet first, who can advise the correct dosage and best brands of supplements to use.