Can Dogs Drink Milk?
Caution — milk is not toxic to dogs, but most adult dogs digest lactose poorly: diarrhea, gas, and stomach upset are common. If you offer any, try a very small amount; if it causes trouble, give none.
Last reviewed: July 24, 2026
The lactose problem
After puppyhood, the enzyme that digests lactose (lactase) declines. A bowl of milk therefore turns into gas, gurgling, and diarrhea within hours for many adult dogs. Tolerance varies: some handle small amounts fine, others react to a single slurp.
If you want to test it, start with a spoon or two and watch for 24 hours. Lactose-free milk or pet-specific milks are safer options. Full-fat milk and sweetened or flavored milks — especially chocolate milk, which contains cocoa — should never be given.
Puppies and milk
Puppies drink their mother's milk; an orphaned puppy should not get cow's milk — its nutrient balance and lactose profile are wrong. Use a puppy milk replacer recommended by your veterinarian instead.
Frequently asked questions
My dog drank milk and got diarrhea — what should I do?
Keep fresh water available to prevent dehydration and stop the milk. See your veterinarian if diarrhea lasts beyond 24 hours, turns bloody, or comes with lethargy.
Can I give lactose-free milk?
Yes, in small amounts it is the safer option. Mind the extra calories though; water should always be the default drink.
Why is chocolate milk extra dangerous?
On top of lactose it contains cocoa (theobromine) — chocolate is toxic to dogs. Chocolate milk is never okay.
Related answers
Sources
This guide is based on publications from the following veterinary bodies. Where sources differ, we take the more cautious position; the final decision is always your veterinarian's.