Golden retriever sitting beside a large bowl of fresh water and a small dish holding a splash of milk in a sunny kitchen

September 28, 2026

Can Dogs Drink Milk?

Dogs can have a little milk as an occasional extra, but they don't need it, and some dogs digest it poorly. The ASPCA warns that milk can cause digestive upset because pets make little lactase.

Goat milk for dogs is often suggested as the gentler choice. It has slightly less lactose than cow's milk, not zero. Keep any milk small and occasional, and water as the everyday drink.

Why does milk upset some dogs?

It comes down to lactose, the natural sugar in milk, and lactase, the enzyme that breaks it down in the gut.

The ASPCA's guidance is direct. Pets do not have significant amounts of lactase, so milk and other dairy products can cause digestive upset.

Puppies meet lactose from their first feed. An analysis of dog milk found lactose is its main sugar.

How much lactase an adult dog keeps is less clear. The published research is thin, and it points in more than one direction.

Are some dogs better at digesting milk than others?

Possibly, and this is one of the more surprising corners of dog science.

A 2011 study that compared intestinal tissue found dogs had 1.6 to 3.1 times more lactase activity than cats in the upper and middle small intestine. The authors concluded dogs have a higher potential capacity to digest carbohydrates than cats.

Genetics may play a part too. A 2021 study in Molecular Biology and Evolution sequenced 242 European dogs and found a variant in the lactase gene that is almost universal in Middle Eastern and European dogs.

The researchers found it raises lactase gene activity, and they place its spread after dairy farming took hold in central Europe. They suggest it may help those dogs digest milk-based diets.

That study measured genes, not how any dog handles a bowl of milk. Your own dog is the better guide: start small and watch.

Is goat milk better for dogs than cow's milk?

It has a little less lactose, and that is the clearest difference the evidence supports.

A 2019 analysis of retail milk in Nutrients found goat milk carried 4.13 g of lactose per 100 g, against 4.52 g in cow's milk. That is roughly 9% less.

Per 100 g	Goat milk	Cow's milk
Lactose	4.13 g	4.52 g
Protein	2.85 g	3.27 g
Fat	3.58 g	3.49 g

The same paper notes that claims about goat milk being easier on sensitive bodies mostly rest on anecdotal evidence.

We searched PubMed and the veterinary bodies listed in our sources and found no controlled study comparing goat and cow's milk in dogs. If a label promises more, we could not find the research behind it.

Cats get the same question, and the answer there is similar. Our guide to can cats drink milk covers the feline side.

How much milk can a dog have?

Think of milk as an extra, measured against your dog's daily calories. The WSAVA advises that all extras together stay under 10% of a dog's daily calorie intake.

That budget is smaller than most people expect. WSAVA's own table puts it at about 47 calories a day for an average healthy 10 kg (22 lb) adult dog.

Here's the number that surprises people. WSAVA lists an ounce of cheddar cheese at 120 calories, more than twice that 10 kg dog's whole daily allowance for extras.

Milk has calories too. Check the label on whatever you pour, and count it toward the day's extras.

Start with a small amount the first time, and watch how your dog does over the next day.
Keep it occasional. WSAVA is clear that extras should never replace a meal.
Fresh water stays the main drink. The Merck Veterinary Manual says clean, fresh water should be available at all times.

For scale, Merck puts the water most mammals need at about 44 to 66 mL per kg of body weight a day in a comfortable temperature. For a 10 kg dog, that is roughly 2 to 3 cups.

Dogs eating mostly canned food generally drink less than dogs on dry food, Merck adds, because the food itself carries water.

What about lactose-free milk?

In lactose-free milk the milk sugar has already been broken down, which takes lactose out of the question.

Berry Good Milk is made for cats and dogs. It is lactose-free cow's milk with added lactase, and it provides taurine, calcium, vitamins D3 and E, omega-3, CoQ10, glucosamine and cranberry extract.

It comes ready to pour, so there is nothing to mix. It still counts toward the day's extras, so measure it against the calorie budget above.

One limit worth knowing: lactase breaks down milk sugar only. Lactose-free milk still contains milk protein, so it is no help to a dog that reacts to milk protein.

Can puppies drink cow's milk?

A puppy that is still nursing needs its mother's milk, or a puppy milk replacer if she isn't there. Cow's milk, goat milk and everyday lactose-free milk are not replacers.

The Merck Veterinary Manual states that commercial milk replacers beat homemade versions, and that none equals the mother's milk. Choose one made for puppies.

The FDA urges extreme caution when using a milk replacer in a species other than the one on its label. Once weaned, puppies move on to a complete puppy food, covered in our guide on what to feed a puppy.

Call your vet promptly if your dog or puppy:

has an upset stomach or loose stool that doesn't settle
seems uncomfortable, bloated or unusually quiet after drinking milk
is a nursing-age puppy that isn't feeding well or gaining weight
has had chocolate or anything sweetened with xylitol

Questions new puppy parents ask

Is goat milk good for dogs?

It has about 9% less lactose than cow's milk in one analysis, but it still contains lactose. No controlled study we found shows it is better for dogs.