Can dogs drink a small amount of milk?

Some dogs tolerate a small amount without any obvious reaction, but there is no reliable way to know in advance which dogs will and won't react badly. Given that milk offers little nutritional benefit to a dog, it is simpler to avoid it altogether than to test your dog's tolerance.

Is lactose-free milk safe for dogs?

It removes the specific sugar most dogs struggle to digest, so it is generally better tolerated than ordinary milk. It is not something a dog needs, but as an occasional treat it carries much less risk of an upset stomach than regular milk.

Why can puppies drink milk but adult dogs can't?

Puppies produce an enzyme called lactase that lets them digest their mother's milk, but most dogs make far less of it once they are weaned onto solid food. That is why milk that caused no problem in puppyhood can upset the same dog's stomach as an adult.

My dog drank milk and has diarrhoea, what should I do?

This is a common and usually short-lived reaction to lactose that most dogs settle from within a day or so without treatment. Withhold milk going forward, and ring your vet if the diarrhoea continues beyond a day, is severe, or your dog seems otherwise unwell.

Is cheese as bad for dogs as milk?

Cheese generally contains less lactose than milk, particularly harder cheeses, so many dogs tolerate a small amount better than they tolerate milk. It is still rich and calorie-dense, so treat it as an occasional small treat rather than a regular addition, and watch how your own dog responds.

Is milk bad for dogs?

Milk is not classed as toxic to dogs, but for most adult dogs it is not a good idea either. Dogs largely lose the ability to digest lactose, the sugar found in milk, once they are past puppyhood, which means a bowl of milk is far more likely to cause an upset stomach than to do any good.

Why milk usually doesn't agree with dogs

Puppies produce an enzyme called lactase, which lets them digest their mother's milk, but most dogs produce far less of it once they are weaned and moved onto solid food. Without enough lactase, the lactose in milk passes through largely undigested, drawing water into the gut and being fermented by gut bacteria — the combination that causes the classic symptoms of loose stools, wind and stomach cramping.

This varies between individual dogs, and a small amount of milk does not cause a problem for every dog. But because there is no way to know in advance how lactose-tolerant a particular dog is, and because milk offers little a dog's diet actually needs, there is not much reason to find out by trial and error.

What actually happens if a dog drinks milk

The most common outcome is diarrhoea, loose stools, or a windy, uncomfortable dog within a few hours to a day of drinking milk, particularly with more than a small amount. This is uncomfortable rather than dangerous for most dogs, and it typically settles on its own once the milk has passed through their system.

Occasionally a dog with a genuine sensitivity can react more significantly, with more prolonged vomiting or diarrhoea. This is still a digestive reaction rather than the kind of toxicity seen with foods like chocolate or grapes, but it is unpleasant enough that avoiding milk altogether is usually the simpler choice.

When to speak to your vet

If your dog has diarrhoea or vomiting that continues beyond a day, seems unusually severe, or your dog appears generally unwell, off their food, or lethargic, ring your vet rather than waiting for it to pass on its own.

This applies especially to puppies, senior dogs, or any dog with an existing digestive condition, where an upset stomach is more likely to need attention than in an otherwise healthy adult dog.

Safer things to give instead

Things we stock that owners commonly reach for here. Nothing on this page depends on you buying one.

Chicken-Wrapped Milk Stick Dog Treats

Chewy dog treats of soft milk sticks wrapped in real chicken for tasty, protein-rich rewarding.

From£12.99

Turkey Tail Mushroom & Probiotic Powder

A bacon-flavoured turkey tail mushroom and probiotic powder you sprinkle over food. Made to support immunity, energy and gut health, with scoop guidance for every weight from small to large pets.

£13.99

Fast UK delivery

Tarhong Concentric Circle Slow Feeder Bowl for Dogs & Cats

A stylish slow-feeder bowl that encourages healthier, calmer mealtimes — available in blue, grey, or white.

£14.99

Yeast Protection Gut & Skin Supplement For Dogs

A powdered daily supplement for dogs to support normal gut flora and healthy skin, with a measuring scoop.

£14.99

Browse all of Dogs →

Common questions

Can dogs drink a small amount of milk?: Some dogs tolerate a small amount without any obvious reaction, but there is no reliable way to know in advance which dogs will and won't react badly. Given that milk offers little nutritional benefit to a dog, it is simpler to avoid it altogether than to test your dog's tolerance.
Is lactose-free milk safe for dogs?: It removes the specific sugar most dogs struggle to digest, so it is generally better tolerated than ordinary milk. It is not something a dog needs, but as an occasional treat it carries much less risk of an upset stomach than regular milk.
Why can puppies drink milk but adult dogs can't?: Puppies produce an enzyme called lactase that lets them digest their mother's milk, but most dogs make far less of it once they are weaned onto solid food. That is why milk that caused no problem in puppyhood can upset the same dog's stomach as an adult.
My dog drank milk and has diarrhoea, what should I do?: This is a common and usually short-lived reaction to lactose that most dogs settle from within a day or so without treatment. Withhold milk going forward, and ring your vet if the diarrhoea continues beyond a day, is severe, or your dog seems otherwise unwell.
Is cheese as bad for dogs as milk?: Cheese generally contains less lactose than milk, particularly harder cheeses, so many dogs tolerate a small amount better than they tolerate milk. It is still rich and calorie-dense, so treat it as an occasional small treat rather than a regular addition, and watch how your own dog responds.

Sources

Written against guidance published by UK veterinary and welfare organisations. Always confirm specifics with your own vet.

Written by Matt Garnett, who runs Giddy Pets and is a lifelong pet owner — not a vet. This is general information, not veterinary advice, and it cannot replace an examination by the vet who knows your animal. How we write these guides.