Why
Cats lose much of their ability to digest lactose as they grow up, so a saucer of cow's milk often ends in an upset stomach. If you want a creamy treat, lactose-free milk made for cats is the safer choice.
What to do instead
- Fresh water is all a cat needs to drink.
- Use a lactose-free cat milk product if you want a treat.
Watch out for
- Cow's milk can cause vomiting and diarrhea.
- Kittens need kitten milk replacer, not cow's milk.
If your cat ate milk
- Note how much your cat ate and when, and keep any packaging.
- Call your vet, an emergency clinic, ASPCA Animal Poison Control ((888) 426-4435) or the Pet Poison Helpline (855-764-7661).
- Don't make your cat vomit unless a vet tells you to.
Other dairy: quick answers
| Food | Verdict | Short answer |
|---|---|---|
| Cheese | Small amounts | A tiny piece is tolerated by some cats, but most adult cats are lactose intolerant. |
| Yogurt | Small amounts | Plain yogurt in a very small amount may be tolerated by some cats. |
Rules for any new food
- Plain is the rule: no salt, butter, oil, onion, garlic, sugar or sweeteners. Most of the danger in human food comes from what is added to it.
- Keep all treats under 10% of your cat's daily calories . The rest should come from a complete cat food.
- Check labels for onion and garlic powder, which turn up in stock, gravy, baby food and seasoned meat.
- If your cat has a health condition, such as diabetes, kidney disease or a sensitive stomach, ask your vet before adding any new food.
Frequently asked questions
Is milk safe for cats?
Best avoided. Many adult cats are lactose intolerant, and cow's milk can cause vomiting and diarrhea.
What should I do if my cat ate milk?
Most cats are fine after a small amount, but watch for vomiting, diarrhea or a change in behavior, and call your vet if anything worries you.
Sources
- PetMD, "Human Foods That Are Dangerous for Cats" (reviewed by Nicole Silva, DVM)
- ASPCA Animal Poison Control, "People Foods to Avoid Feeding Your Pets"
- Embrace Pet Insurance, "7 Foods You Can Share With Your Cat" (Chyrle Bonk, DVM, updated Apr 10, 2025)
Checked October 17, 2026. We are a reference, not a vet: if in doubt, call yours. How we check.