Here’s why you should think twice before letting your pets split a meal.

Have you run out of cat food and are now wondering if Fido's food can work as a substitute for Fluffy? Or did you catch your cat snagging some kibble from the dog's bowl and are now concerned her digestive system will pay a price? The good news is dog food isn't toxic to cats. But while dog food is generally considered to be safe for cats, there are other questions to consider before pouring your purring pet a bowl:

  • Are there any nutritional benefits to feeding cats dog food?
  • Are there any risks with feeding cats dog food? Will my cat get sick from eating dog food?
  • How much dog food can cats safely eat?

We paired up with the University of Missouri Small Animal Clinical Nutrition Service in Columbia, Mo., to better understand the risks.

cat eating dog food out of onlooking golden retriever's bowl
Credit: chendongshan / Getty

Is It Safe for Cats to Eat Dog Food? 

Dog food isn't toxic to cats, so if your feline eats a small amount once or twice, it shouldn't make themsick. However, The Clinical Nutrition Service says there are several important caveats to keep in mind:

  1. Dog food is considered to be safe for healthy cats. So if your cat has a health condition, such as cancer or kidney disease, this general rule doesn't apply. 
  2. Every cat is unique and can vary a great deal when it comes to tolerating certain foods. "Cats must be considered individually," the Clinical Nutrition Service explains, "as some cats may consume a particular food item with no issue and another cat may consume the same item and develop vomiting, diarrhea, or other adverse signs." 
  3. Portion size and frequency matter. If eating dog food becomes a long-term habit for your cat and starts replacing cat food, your pet won't be able to get the nutrients her body needs, and her health will begin to suffer. 

Are There Any Nutritional Benefits to Feeding Cats Dog Food?

Dogs and cats don't just differ with regards to behavior—they're unique in their nutritional needs, too. Cats are obligate carnivores, meaning they rely on nutrients found only in animal products. Dogs, on the other hand, are omnivores. Their nutrient needs include both animal and plant (i.e. grains, vegetables) products. 

This means a commercial food that's complete and balanced for a dog won't be complete and balanced for a cat. For example, taurine is an amino acid cats must get in their diet to survive. Dogs, on the other hand, are able to produce their own taurine. 

Cats are also prone to dehydration without proper water intake, which is why many experts recommend feeding cats wet food. If your cat is regularly filling up on your pup's dry kibble instead of her own canned food, she may not get all the water intake she needs.

Should Cats Eat Dog Food?

Bottom line: dog food can't replace cat food. And it's not a matter of marketing magic aimed at getting you to spend more money and lug more bags around—the two products really are different and are not interchangeable. 

"Cats have specific nutrient requirements that must be met by their diet," the Clinical Nutrition Service explains. "The simplest and most convenient way to meet the nutrient requirements of a cat is to provide them with a complete and balanced commercial diet formulated by a board-certified veterinary nutritionist or an individual with a PhD in animal nutrition." 

If you're unsure whether your cat is getting the nutrients she needs from the food she eats every day, bring up your concerns with your veterinarian. They can help you find good options for your pet based on her nutritional needs.

What To Do if Your Cat Eats Dog Food

If your healthy cat nabs a few bites from Fido's bowl, there's usually no need to worry. Be sure to keep an eye out for any serious reactions such as diarrhea, vomiting, or weight loss and reach out to your vet if there are signs of illness. Eating dog food may be more problematic if your cat has an allergy or underlying health condition.

How to Keep Dog Food Away From Your Cat

Let's face it: Cats are stubborn and you may just need to work a little smarter to keep your kitty away from her canine sibling's food. If you have a large dog, an elevated bowl may help keep your cat away. One of the easiest solutions is to separate your pets' feeding locations. If their bowls are far apart in different rooms, they'll be less likely to steal a bite from the other's meal. It may also help to use a gate or closed doors to separate them during feeding time.

If eating dog food becomes a habit, a trip to the veterinarian may help uncover underlying issues. Make sure to note the brand of dog food and watch for other unusual behaviors that may indicate your cat isn't feeling well to help your vet diagnose the issue.

Speaking of feeding time, another solution is to avoid free feeding your pets. Pick set times to feed your pets, then supervise and remove their bowl once they've finished their meal. Investing in automatic feeders can also help prevent excess food from sitting around for your feline to steal.