Why Do Cats Like Fish?

Why Do Cats Like Fish

Why do cats like fish?

Cats like fish for the following reasons:

1. Cats started to like fish due to co-evolving with humans.  

Cats started to like fish when they were first lured to the homes of ancient Egyptians with fish as food although the so-called domestication of cats was said to have started in the Middle Eastern deserts around 10,000 years ago. Also, because of this co-evolution with humans, cats have learned to realize that they can easily partake of the fish caught by people and they don’t have to hunt actively and thus saved energy.

2. Cats are opportunistic feeders. 

Cats are known to utilize and eat whatever food source is commonly available in their surroundings and this includes the food that people give them such as fish bones and fish leftovers as well as garbage that they see on streets and garbage bins. 

3. Cats are attracted to the strong smell of fish. 

While cats only have 470 taste buds and have a limited ability to detect various tastes and flavors,  their sense of smell is extraordinary because it’s 9 to 11 times stronger than a human’s.  This may well explain why, aside from various other odors and scents, cats are drawn to fish because of its strong smell and aroma. 

What types of fish should you feed your cat?

Cats can eat any type of fish if they’re not allergic to it. The most recommended types of fish for consumption are tuna and salmon because they’re good sources of Omega-3 and fatty acids. However,  these types of fish have high mercury content. Cod, flounder, and halibut are smaller types of fish with less mercury and they’re presumed to be safer for cats to eat.  Take extra precautions when giving canned fish because of the high sodium content. 

These are the health benefits of nutrients from fish for cats:

  • protein – helps cats to stay healthy, builds tissues, regulates pH balance, and provides energy
  • taurine – an amino acid that controls heart rhythm, vision, reproduction, and digestion
  • Omega 3 fatty acids –  keeps the coat glossy and shiny, reduce inflammatory conditions like asthma, inflammatory bowel disease, arthritis, and skin disease, and lessen the risk of cancer 

Do some cats hate fish?

Do some cats hate fish
Image: istockphoto.com / Okssi68

Yes, there have been pet parents who attest that their cats don’t eat fish. It depends on each cat’s preference for food. It may also be because some cats were not introduced yet to a fish-based diet. Some pet parents also claim that their cats do not eat salmon or tuna while some others prefer pork or chicken meat instead of fish. Some cats are also allergic to fish and will avoid eating fish altogether. Cats that are allergic to fish may suffer the following symptoms: inflamed skin, vomiting, diarrhea, and hair loss. and scratching, wheezing and sneezing or coughing. 

How often should your cat eat fish?

Cat experts recommend that you should only give fish to your cats at least two or three times a week.  This is because while fish contains taurine and protein which are important nutrients for cats, it also contains thiaminase that breaks up thiamine or Vitamin B1 which is an essential part of a cat’s nutritional requirements. If cats are thiamine-deficient, their nervous system becomes prone to fatal damage.   Fish also has mercury which can be toxic for cats when taken in large quantities as it may lead to urinary tract infection (UTI) and hyperthyroidism. 

Why must cats only eat fish in moderation?

Cats should only be given fish in moderation because the latter contains heavy metals and toxins such as flame retardant chemicals and mercury. These toxins could cause a thyroid disorder which may lead to muscle wasting, excessive metabolism, and even death.  Also, farmed fish are heavily treated with antibiotics that remain in the fish’s flesh. 

Can a cat be given a vegetarian diet instead of fish?

No, cats can’t be given a vegetarian diet because they’re obligate carnivores and they need meat in their diet. They’re designed to consume meat, unlike dogs which are referred to as omnivorous carnivores because they can digest plant matter. Cats only have a few molars that are needed to grind plants, unlike herbivores that have jaws that help in grinding food and plants. Unfortunately for cats, they don’t have the enzyme amylase in their saliva and their short intestines don’t allow them to absorb plant nutrients. 

Why do cats stare at fish in an aquarium? Does it mean they like to eat it?

Most cats do instinctively watch and stare at fish inside an aquarium or fish tank because their interest is piqued by the fish swimming about in the water.  But it doesn’t always mean that they’re thinking of eating the fish in the tank. Most of the time, watching the fish swimming in circles is pure entertainment for cats and they’re staring at it because it got their attention. However, given the chance and pure luck, some cats will attempt and succeed at catching the fish which eventually becomes a quick snack! 


Cats like fish because they learned to co-evolve with humans who hunt and eat fish, thus, cats have also come to like and eat fish. However, not all cats like fish because each cat has its own preferences while some others are allergic to it.  While fish contains nutrients that are essential for cats like taurine, Omega 3, and thiamine, it should be given in moderation only as over-consumption of fish could lead to health issues like hyperthyroidism and urinary tract infection.