Can dogs eat milk? And cats?
Many adult dogs are lactose intolerant; expect digestive upset, not poisoning.
The saucer-of-milk image is a myth: most adult cats cannot digest lactose.
Milk is not toxic to dogs or cats, but most adults of both species lose the enzyme that digests lactose after weaning, so milk commonly causes diarrhea and stomach upset. Kittens need kitten milk replacer, not cow's milk. If you want to share, lactose-free pet milks exist, but plain water is all they actually need.
Signs to watch for
- Diarrhea
- Gas
- Bloating
- Vomiting
Sources: ASPCA Animal Poison Control people-foods guidance, Merck Veterinary Manual, Pet Poison Helpline. Verdicts are conservative by design: where evidence is thin we choose the stricter rating.
This is general educational information, not veterinary advice. When in doubt about your own pet, ask your veterinarian.
If your pet just ate something risky, act now: call your vet, ASPCA Animal Poison Control at (888) 426-4435, or Pet Poison Helpline at (855) 764-7661 (consultation fees may apply).