Can I Feed My Cat Dog Food?

Dog Food and Cat Food Are Not Created Equal

Photo of cats eating Natural Balance Platefulls
My Three Boys Eating Natural Balance Platefulls. Photo Credit: © Franny Syufy

You have a cat and a dog. Dog food is often cheaper than cat food, and it usually smells a lot less fishy. So why not feed your pets the same food?

While an occasional bite of dog food certainly will do no harm, exclusively eating dog food simply won't provide your cat with the nutrients she needs. In the long run, a steady diet of dog food will make your cat sick -- and your vet bills will more than offset any money you might have saved!

The Difference Between Dogs' and Cats' Nutritional Needs

Dogs are omnivores. They naturally eat a wide range of foods, with meat being just one element of their diet. Cats are carnivores -- meat eaters, just like T. Rex. This difference means that dogs' bodies require a fairly balanced diet of protein and fiber (from plant-based foods) while cats require very high protein, meat-based diets. It also means that dogs and cats process food very differently.

Let's break it down a bit more.

How Much Protein Do Cats Need?

About 45% of a cat's diet should be protein, while humans and dogs require much less.  What's more, while humans and dogs can get some of their protein from plant-based foods, cats must get all of their protein from meat or fish.

Meat-based proteins include an amino acid called taurine. Taurine is absolutely essential to cats -- and is available only in proteins that come from animal tissues.

Without sufficient taurine, cats can suffer from hair loss, tooth decay, heart issues, and even blindness. 

When a cat eats dog food, it gets only a small percentage of the meaty protein it needs. It must eat twice as much dog food for the same protein value -- which would make for a very fat cat. A good cat food, however, includes enough meat-based protein to keep cats healthy and slim.

Necessary Nutrients

Cats need arachidonic acid, thiamine, and niacin, which are all important for optimal feline health. Because they are carnivores, cats must get these vitamins from meat. Even when a dog food contains these vitamins, they may be in a form that cannot be processed by cats. 

Carbs and Water

Cats don't need carbohydrates -- but they do need water. If a cat eats dry dog food on a regular basis, they get plenty of carbs and relatively little water. Cats, in general, have a relatively low drive to drink water (perhaps because of their origins in drier parts of the Earth).  Cats that eat too many carbs can quickly become overweight, and cats that have too little water can develop urinary tract problems. 

Texture and Flavor

While cats will sometimes take a nibble from your dog's bowl, the reality is that dogs are more attracted to cat food than the other way around. That's probably because cats are more tuned into the smell, taste, and texture of food. 

For more information on the importance of the right food for cats, please read "Why All the Fuss About Cat Food?"