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Can Fish Eat Cheese? (Goldfish, Betta, Koi, Guppy, Etc.)

Cheese is a dairy product that you can see on pizzas, burgers, and various other dishes. Different species of cheese have different flavors, textures, and aromas but, all cheese consists of proteins and fats from milk.

On the other hand, fish foods contain fat, vitamins, and minerals that a fish needs to develop.

Can fish eat cheese?

Fish cannot eat cheese. Fishes do not have the required enzymes to break down the cheese components. Therefore, they cannot digest most of the products present in cheese. Additionally, the chemicals and additives in processed cheese may be harmful to fish.

Cheese is a dairy product that goes through processing before it turns into the final product. As a result, it requires some special enzymes to break down all the constituents of cheese. In humans, the enzymes are present in the stomach, which helps the digestion of cheese.

However, in fishes, these enzymes are not present. A fish’s digestive system is adapted to digest food products found underwater and native to them, such as seaweed, smaller fishes, insects, etc. Cheese is a foreign substance to them and, hence, they cannot fully digest cheese.

As cheese is a dairy product and not found underwater, it is not native to fishes, and they cannot break it down. So, most experts advise against feeding a pet fish cheese or other dairy products. 

Cheese may attract fish as it is a protein source but, it is harmful to them as they cannot break down cheese to digest it.

As mentioned before, cheese has a lot of chemicals in it. These chemicals are required for the production of cheese. However, some of these chemicals can be harmful to a fish.

Why is cheese bad for fish to eat?

There are a few reasons why cheese is detrimental for a fish to eat. The reasons are:


Fishes are creatures that live in water bodies. They are adapted to eat food found underwater. As a result, their digestive system is adapted such that it can only digest the food that is native to the fish. Cheese is a dairy product that cannot be found underwater.

Therefore, the digestive system of a fish cannot break down cheese and animal fatsin the stomach. So, even though a fish may eat cheese because of the proteins, it may be harmful to its body.

Unhealthy food:

Cheese contains a lot of animal fats and proteins. It is made from milk by processing with bacteria and enzymes. 

A fish diet does not consist of high fats as they do not need so much fat to live. Since cheese contains a lot of fat, it may harm a fish by making it obese. Obesity will cause the fish to sink to the bottom and make them unable to swim.

Harmful additives:

It is well known that cheese contains chemicals. These chemicals are required for the production of cheese. Moreover, it also has a lot of bacteria that are needed in the process of making cheese. Both the chemicals and bacteria may be harmful to a fish. 

Also, introducing cheese to an aquarium will introduce foreign bacteria into the water. Bacteria may contaminate the water.

What fish can and can’t eat cheese?

People who own pet fish are often confused about what kinds of fish can and cannot eat cheese. Below is a list of popular fish kept as pets and if they can eat cheese.


Bettas like eating foods that contain a lot of proteins. So, even though they might like cheese because of its high protein values, it is harmful. Bettas can only eat foods that do not have any additives or chemicals. 

Since cheese has chemicals, it cannot eat cheese.


Koi fishes are a popular type of fish that are farmed by a lot of people. Some people also keep koi fishes as pets. Although koi fishes are adventurous eaters, they cannot eat dairy products. 

They cannot eat dairy products because they are not evolved to digest animal fats. As a result, they cannot eat cheese.


Goldfishes are the most common fish kept as pets. These fishes are mainly fed fish foods but may eat human foods infrequently when fed. A goldfish can eat a tiny chunk of cheese without any consequences but, it should not be fed cheese too often.

Goldfishes cannot digest cheese and hence, will be harmed.


Wild fishes that are found in ponds and lakes eat cheese when it is available. Many people use cheese as bait to attract wild fish. Even though they are attracted to cheese, this does not mean they can be fed cheese. 

Wild fishes, like all fishes, cannot digest animal fats. Therefore, they cannot eat cheese regularly.


Tropical fishes are fond of fish food. They only tend to eat fish foods and nothing else. However, most tropical fishes also like plant matter. Besides fish foods and plant matter, tropical fishes do not eat anything else. 

Cheese is harmful to tropical fish as it is a fish and cannot digest animal fats.


Wild Oscar fishes eat fish foods and plant matter. They can be fed cucumbers and zucchini in small chunks. Oscars like the taste of cheese. So, when they are provided cheese, they will eat it. But again, Oscars are fish too. 

Therefore, they cannot also digest animal fats present in cheese. As they cannot digest animal fats, it will have adverse effects on their digestive system.


Similar to goldfishes, guppies are also popular as pet fishes. They love eating fish foods and plant matters like cucumber, carrots, cauliflower, cabbage, etc. They cannot eat human foods other than plants and vegetables. 

Also, they cannot eat processed foods like pretzels, cereals, and cheese. Processed foods affect their digestion negatively and harm them.

Can you feed a fish bread or dairy?

You cannot feed fish any either bread or dairy products. Fish and bread are both human foods. Therefore, they cannot be fed to fish.

Bread contains a lot of chemicals. Moreover, they also have yeast, a type of fungus which makes the bread soft and fluffy. These chemicals and fungi are harmful to fishes, so, should not be fed to a fish.

As for dairy products, they contain animal fats and proteins. Although fishes may eat dairy products when provided, they do not have a complex digestive system capable of breaking down dairy products. As a result, it will be harmful to them to eat dairy products.

What should you not feed fish?

Besides dairy and processed foods, some foods should not be fed. Those foods are given below:

Fatty foods:

Do not feed fat-rich food to fish. Fishes do not need a lot of fat to survive, and excess fat will be detrimental to their health. When a fish eats fatty food, fat builds up around its heart. Herbivore fishes can eat 3% of fat, while carnivore fishes can eat 6%. 

If the fat content is more, then it will be harmful.

Infected live feed:

Some fishes are carnivores and will feed on the live feed. Before these are introduced in the aquarium, check for any infections. You do not want to introduce infection in the aquarium. The unhealthy live feed will have severe consequences on the fish.

Moist fish food:

You should store fish food in a dry and warm place. If moisture reaches the fish food, it will disintegrate the food. As a result, bacteria will grow on the food. When the fishes eat bacteria, it will live in their body and cause them to expire.

Final thoughts

In conclusion, fishes cannot eat cheese. Cheese contains chemicals and additives that may be harmful to a fish’s digestive system. Moreover, as a fish cannot digest animal fat, it cannot eat cheese. For such reason, do not feed dairy products to a fish.