Maybe you’ve wondered before what the difference is between the cat food, dog food, and rat food in your pantry. It would be so much easier if you could just feed them all the same food, after all.
But is it safe to feed cat food to your pet rats? What’s the best food for rats?
If there’s really nothing else left in the house to feed your rats with, giving them a bit of cat food won’t hurt. There is nothing inherently toxic for pet rats in cat food. However, cat food was not designed with your rats’ nutritional requirements in mind and does not make the best choice of food for your mischief.
If you want to find out why cat food is not the best option and what to feed your rats instead, just read right on.
Can You Feed Your Pet Rat Cat Food?
Is Cat Food Safe for Rats?
Let’s first have a look at what cat food contains. This will vary by brand, obviously, but in general the composition of cat food looks something like this:
A protein source (normally meat or meat by-products) plus grains and/or vegetables. Sometimes, fructose or glucose syrup is added as well – which is neither good for your cats or your rats! Some cat foods may also contain fruit, herbs or spices.
The meat, grain and veg used for cat food are generally safe for rats, too. There is no inherently toxic ingredient in cat food. So, if your rats ended up nibbling on some cat kibble by accident, there’s no harm done.

But does that mean that you can feed your mischief cat food?
I wouldn’t recommend it. Cat food was tailored to the nutritional requirements of cats, who are pure carnivores. Therefore, cat food has a very high protein content.
The Association of American Feed Control Officials (AAFCO) recommends a protein content of no less than 26% for cats1 – many cat foods have even higher levels. By contrast, and adult rat only needs about 14-16% of protein in their diet2. Feeding your rats a high-protein diet may have detrimental effects on your their health3,4.
Not only the macronutrients are relevant – pet food is generally formulated to meet the vitamin, mineral and trace element requirements of the species. A rat has very different micronutrient needs than a cat, so feeding your mischief cat food could lead to malnutrition in the long run.
Can Rats Eat Cat Food in a Pinch?
Let’s say it’s Sunday, all the shops are closed in your town, and you’re all out of rat food. Can you give them some cat food instead? You could, but there are better options.
If it’s just a matter of making do for a day or two, your rats are probably better off if you give them their usual vegetables and supplement them with some cooked rice or pasta, or boiled potatoes or sweet potatoes.
Add in a little bit of boiled egg or low-sodium cottage cheese if you have growing, pregnant or lactating rats.

What About Dog Food?
Dogs are omnivores, just like rats. Therefore, you might expect that dog food is better suited to rats than cat foods – and it is, if only slightly.
Still, many dog foods also contain 20% or more protein, and they are not designed with you rat’s nutritional requirements in mind.
Dog food is not toxic for rats, but it’s not a good choice of food for them, either.
Is Rabbit or Guinea Pig Food Suitable for Rats?

Guinea pigs and rabbits are not omnivores, but herbivores. They therefore rely more on plant matter and less on protein than rats do. Rabbits and guinea pigs can digest herbs, twigs, barks, seeds, and roots easily.
While rats may be able to eat some of the components of a rabbit or guinea pig’s diet – especially the seeds – it will not meet their protein, fat and carbohydrate requirements.
Some rabbit or guinea pig food ingredients may be downright indigestible to rats and could cause gastrointestinal upset.
What is the Best Food for Rats?
As we’ve discussed, the best food for any pet is one that was designed with the species’ nutritional needs in mind. You should offer your rats a high-quality rat pellet food with at least 15% protein and a fat content of around 5%.

Additionally, your rats need fresh vegetables every day, and some fruit to complement their diet. Some examples for suitable vegetables are: broccoli, cauliflower, kale, potatoes (cooked) and sweet potatoes (cooked), bell pepper, cucumber, pumpkin, squash and mushrooms. Safe fruits include pears, apples, kiwis, bananas, melon and watermelon, avocado, and berries (strawberries, blueberries and raspberries).
Growing pups and pregnant or lactating dams may benefit from additional protein in their diet. This can either occur through feeding a specifically designed pellet food, or by adding boiled egg, meal worms, quark or low-sodium cottage cheese to their diet.
To Sum Up
A bit of cat food is not harmful to your mischief, but there is no nutritional reason to offer it to them.
Your rats will thrive on a rat pellet mix, supplemented by fresh daily vegetables and some fruit.
Additional treats are great for bonding and teaching tricks, but not strictly necessary from a nutritional standpoint. To find out more about what foods to offer your rats, browse our “can rats eat…?” articles!
Resources:
1. MSD Vet Manual. AAFCO Nutrient Requirements for Cats. https://www.msdvetmanual.com/multimedia/table/aafco-nutrient-requirements-for-cats.
2. National Research Council (US) Subcommittee on Laboratory Animal Nutrition. Nutrient Requirements of Laboratory Animals: 2, Nutrient Requirements of the Laboratory Rat. . 4th Revised Edition.: Washington (DC): National Academies Press (US), 1995. https://www.ncbi.nlm.nih.gov/books/NBK231925/
3. Kołodziej U, Maciejczyk M, Niklińska W, et al. Chronic high-protein diet induces oxidative stress and alters the salivary gland function in rats. Arch Oral Biol 2017;84:6-12. https://pubmed.ncbi.nlm.nih.gov/28926744/.
4. da Rosa Lima T, Ávila ETP, Fraga GA, et al. Effect of administration of high-protein diet in rats submitted to resistance training. European Journal of Nutrition 2018;57:1083-1096. https://doi.org/10.1007/s00394-017-1391-5.

Nina has a degree from the Veterinary School in Zurich, with a special focus on microbiological research. Nina has a passion for sports, nutrition and the outdoors and she loves all pets, but rats have a special place in her heart. When she’s not working or reading and writing about all things related to pet health, she loves to travel and surf.
As a small animal veterinarian, Nina is your go-to expert on pet health and nutrition.