Can Cats Eat Dog Food? Why It Fails Cats Long Term

By Tailwisp Editorial TeamUpdated October 20, 20264 min read

In homes with both cats and dogs, food bowls inevitably get raided. Cats nibble from dog dishes, and dogs gobble cat food. The occasional swap rarely hurts, but it is worth understanding why the two diets are different, and why a long-term mix-up can cause real harm.

How cat and dog food differ

Dogs are omnivores in the nutritional sense. They can digest a wide range of foods and make some nutrients in their own bodies. Cats are obligate carnivores, with a metabolism that depends on animal tissue. Key differences include:

• Protein. Cats need higher protein than dogs, and they use amino acids as an energy source continuously.
• Taurine. An amino acid essential for heart muscle, vision and reproduction. Cats cannot make enough, so it must be in their food. Cat foods are supplemented with it, but dog foods need not be.
• Arachidonic acid. An essential fatty acid that cats must get from animal fat.
• Vitamin A. Cats cannot convert plant beta-carotene into vitamin A efficiently, so they need it preformed from animal sources.
• Niacin and other B vitamins. Cats need more than dogs.

Dog food is formulated to meet dog standards, so it commonly falls short on several of these for a cat.

Risks of long-term dog food

When a cat eats dog food as its main diet, the most serious risk is taurine deficiency. It can lead to dilated cardiomyopathy, a disease in which the heart muscle weakens and the heart enlarges, and to a type of retinal degeneration that can cause blindness. Other signs include poor coat, weight loss and weakness. With early detection and a switch to proper diet and supplements, some effects can be reversed, but vision loss is often permanent.

Quick reference

Why your cat is sneaking dog food

Cats may prefer dog food because it smells strong, because it is easy to reach or because a bowl of food that is always available is hard to resist. Some cats also like the different texture. If your cat is eating dog food because it is hungry, check that its own portions are right. Our cat food amount calculator can help you review how much to feed.

How to stop food swapping

1. Feed at separate times. Offer meals in set sessions and pick up what is not eaten after about twenty minutes.
2. Feed in separate places. Cats can eat on a high shelf, cat tree or in a room the dog cannot reach. Dogs can eat in another room.
3. Use barriers. A baby gate that the cat can jump over but the dog cannot is a classic fix.
4. Try a microchip feeder. These bowls open only for the registered pet's chip or tag.
5. Stop free feeding. Leaving food out all day makes raiding easy and also makes weight management harder.

What if the dog eats the cat food?

Cat food is rich in fat and protein, so a few bites will not harm most dogs, but large amounts can cause diarrhea, vomiting or pancreatitis. If your dog eats a lot, contact your vet.

Signs your cat's diet is not right

Weight loss or gain, a dull coat, vomiting, diarrhea, lethargy, vision changes, breathing difficulty or a cat that eats poorly all call for a veterinary visit. If your cat has been eating dog food regularly, tell your vet, who may recommend a diet change or test for taurine levels. Our cat health guides explain more about these signs.

Special cases

Kittens. Growing kittens need more protein, fat and specific nutrients than any adult food, and adult dog food is a poor match. Use food labeled for kittens or for all life stages.

Senior cats. Older cats may lose weight and muscle, and they often need highly digestible protein. Dog food is not a good fit. See our senior cat care guides.

Cats with kidney disease or other conditions. These cats may be on a prescription diet. Mixing in dog food can undermine the plan, so ask your vet before changing anything.

Reading labels

A complete cat food will say it is formulated to meet nutritional levels for cats, or has passed feeding trials for cats. A dog food label will not make that claim for cats. Check the guaranteed analysis too: cat foods generally list higher crude protein than dog foods.

Choosing a complete cat food

Look for a statement on the label that the food is "complete and balanced" for your cat's life stage, meaning it meets a recognized nutritional standard. Ask your vet if you are unsure. Our cat nutrition library is growing, and the free cat food and plant safety checker can help with specific foods.

This article is general educational information, not veterinary advice. Every cat is different. If your cat is unwell, or you are unsure about a symptom, diet change or medication, contact your veterinarian.