Can Rats Eat Cat Food?

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If you have rats and cats, you may be wondering whether it’s safe for your rat to eat the cat’s food and save you from having to buy in special food for your rats? Well, we don’t think it’s a great idea to do so and here’s why:

Can rats eat cat food? Yes, they can eat very small quantities of cat food as part of a much bigger, balanced diet. But can they live on it? Absolutely not. It contains too much fat and too much protein and could lead to an early grave for your rats. So, let’s take a look at what is safe for your rats to eat and what is not.

The Basics Of Feeding Rats

Rats are pretty easy going about their diet, but this isn’t always a good thing. They will happily chow down on a lot of things that aren’t very good for them if you allow them to.

The ideal diet for a pet rat is going to be one based on rat’s natural diet or one which uses a specially-formulated rat food for their health. If you do opt for the special formula, then it’s OK to add the occasional treat to their diet.

If you try to construct a rat’s diet by yourself, you may end up with malnourished rats (e.g. rats lacking certain vitamins or minerals) and it’s also very likely that you will end up with obese rats too (rats are a bit like humans in this respect and will, if allowed, eat pretty much anything that you put in front of them, even when it’s not very good for their long-term health).

Buying Food For Rats

You should buy formula food for rats unless you have plenty of time and patience on your hands to recreate their natural diet. Most formula food comes in either pellets or in a block.

Some people claim that genetically modified ingredients in pellet food can cause cancer in rats but there is absolutely no evidence of this. In the same way that there is no evidence that genetically modified food is dangerous to any other creatures.

These blocks and pellets tend to be made up of seeds and nuts, mainly, which are low in protein, low in fat and relatively low calorie.

You should not use hamster, gerbil, etc. feeds instead of rat food because they may contain alfalfa which rats have real problems digesting.

Can You Feed Rats Other Food Stuffs?

Yes, you can and, in general, you can feed rats pretty much any vegetable fruit or fresh food. However, you shouldn’t give them much more than a teaspoon of anything at any one time because the new food can often lead to an upset stomach for your rat.

You don’t want your rat to have diarrhea, so, go easy on the treats. Here are some treats which are just fine for your rats:

  • Breakfast cereals (but not those with added sugar)
  • Brown rice
  • Cooked beans
  • Cooked lean meat
  • Cooked liver
  • Dog biscuits (small ones)
  • Fruits
  • Mealworms
  • Nuts in the shell
  • Sunflower seeds
  • Vegetables
  • Whole wheat bread
  • Whole wheat pasta
  • Yogurts (those with live cultures are particularly good)

Sunflower seeds and nuts in the shell are a little higher in fat than is good for a rat, so, it’s best to give them these in moderation rather than on a regular basis. Obesity is a genuine problem in rats and just like with people – it can have a long-term negative impact on their health.

Can Rats Have Cat Food As A Treat?

Hey! Cat food isn’t on that list of foods you can feed your rats!

Yes, it’s true. Firstly, you cannot feed a rat only cat food – that would quickly kill your rats. It’s too high in both proteins and fats. Your rat would likely develop protein poisoning.

You could, in theory, feed a rat dog food as long as it was specially formulated for low-fat and low-protein, but this wouldn’t be a brilliant idea and they might still end up malnourished.

You can, however, give your rats tiny amounts of either cat or dog food as a treat. This shouldn’t be a regular treat, but they won’t die from a taste and they might enjoy it very much.

A List Of Foods That Rats Can Only Eat As Small Treats

Cat and dog food are not the only items that ought to only occasionally be given to your rats and only ever in small amounts. Here’s a list of products that you ought to be cautious about before you feed them to your rats:

  • Avocados. Don’t feed your rats the skin or the pit of the avocado – these are poisonous. It’s best to feed them only flesh that has been taken from a point away from both the skin and the pit. In fact, it’s probably best not to feed them avocado at all.
  • Chocolate. Chocolate doesn’t appear to poison rats (which it can other animals such as dogs) but at the same time, vets caution against allowing your rats to gorge on chocolate too.
  • Citrus fruits. There is some evidence that a compound in citrus fruit, D-limonene, is damaging to the kidneys of male rats. You should always wash citrus fruit after you peel it if you share it with your rats and maybe, you should skip it entirely. Mango also contains this compound.
  • Fatty foods and meats. Too much fat in a rat’s diet prevents it from absorbing dietary calcium and can cause oily fur, upset stomachs, and liver disease. In the long run, it can kill.
  • Fizzy drinks. Rats will happily lap up fizzy drinks but unlike you they can’t burp, which means they can end up in pain from trapped gas.
  • Fluorinated/chlorinated water. This means tap water in a lot of places – both fluorine and chlorine are severely toxic to rats. Either used filtered water or bottled water.
  • Potatoes. You shouldn’t feed your rats any part of the potato which is green because solanine (the stuff that makes it go green) is toxic to them.
  • Sticky foodstuffs. Sticky viscous foods like peanut butter represent a choking hazard for rats. It’s best to dilute them if you must share them with your rats and keep a close eye on them while they eat.
  • Sugary foods. Just like in people, there’s not much good to say about the impact of sugary foods in a rat’s diet.

A List Of Foods You Should Never Give Your Rats

There is also a list of food stuff which you should never give to your rats because they can cause severe side effects or even death when your rats eat them:

  • Alcohol. You may enjoy a drink and rats being curious about what you eat/drink might fancy a try. Unfortunately, they can’t handle alcohol like human beings and while tiny amounts might make them drunk, they might also suppress their organ systems and even kill your rats, which isn’t as much fun.
  • Green bananas. There are enzymes in these bananas which can inhibit the digestive process causing severe discomfort.
  • Raw beans or dried beans. These contain hemagglutinin (which breaks down on cooking). This is extremely toxic to rats.
  • Blue cheese. The mold that makes it blue can be deadly to rats.
  • Caffeine. Rats are not natural coffee drinkers and the impact of caffeine on small bodies is dramatically heavier than it is in human beings. Caffeine will often elevate their heart rate so much that it can cause their hearts to collapse under the strain.
  • Citrus peels. There is way too much of that D-limonene in peels for it to be safe to eat.
  • Dried corns. Corn is fine but dried corn has a tendency to be full of fungus and this fungus might give your rats liver cancer.
  • Insects. Yes, wild rats will eat insects, but pet rats don’t, and they may catch parasites from eating insects.
  • Licorice. This causes poisoning of the nervous system in rats.
  • Raw sweet potato. This can turn into cyanide compounds in their stomachs during digestion.
  • Any notably spoiled produce. Spoiled stuff is not fit for consumption – it will be covered in bacteria and fungi that might make the rat sick or even kill it.


Can rats eat cat food? As a treat? Certainly. As their only diet? Definitely not. Cat food isn’t designed for keeping rats healthy and has too much fat and protein for a healthy rodent diet. It can be given as an occasional treat though.

As you can see, there are plenty of options to feed your rats safely and keep them happy and healthy – so, it shouldn’t be too disappointing about the cat food, your rats will still eat an interesting and varied diet.

Darren Black

I'm Darren Black, the owner, and author of I am from Scotland, United Kingdom and passionate about sharing useful information and tips about properly caring for an animal's wellbeing.

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