Why?
Dog food isn't toxic, but it's made for an omnivore. It doesn't guarantee enough taurine, an amino acid cats can't make enough of on their own, and a lack of it can damage the heart and eyes. Dog food also tends to have less protein, and may lack vitamin A, arachidonic acid and niacin in the forms cats need. Over weeks or months, that imbalance can make a cat sick.
How much?
Not as a diet. A few kibbles stolen from the dog's bowl are no problem. If you run out of cat food, one stopgap meal won't hurt, but get proper cat food as soon as you can.
The risks
- Taurine deficiency: heart disease and vision problems
- Not enough protein for a cat
- Lacks vitamin A, arachidonic acid and niacin cats need
- Weight gain from eating from both bowls
- Digestive upset from a sudden food change
Your cat ate some: what now?
A few kibbles or one meal of dog food is no problem: at worst, a little diarrhea or vomiting from the change. Watch for 24 to 48 hours and call your vet if it lasts. If your cat has been eating it regularly for weeks, talk to your vet.
Better options
Feed your cat a complete cat food, and feed your pets in separate rooms or at different heights so each sticks to their own bowl.
Common questions
What happens if my cat eats dog food every day?
Over time, your cat risks deficiencies, especially taurine, which can damage the heart and eyes. Separate the bowls, for example by feeding the cat up high, and check with your vet if it's been going on for a while.
Can I feed my cat dog food in an emergency?
One meal won't hurt if you're out of cat food. Plain cooked chicken is a better stopgap, but get complete cat food as soon as possible.
This information is general and does not replace advice from a veterinarian. If your cat has swallowed something toxic, call your vet or an animal poison control center right away, without waiting for symptoms.