Lactose intolerance in dogs

Lactose intolerance in dogs

Health & Safety

When it comes to food sensitivities and allergies in dogs, these are not always obvious to us as their owners, as digestive symptoms are not always bad enough to make us people notice them; although this is not always the case!

If your dog seems to get a stomach upset after eating something like milk or cheese, or they suffer from diarrhoea if they’re fed something like this, your dog might be lactose intolerant. This is the case for a reasonably high number of dogs overall, and is part of the reason why dairy products aren’t usually used in commercial dog food diets.

This article will talk about lactose intolerance in dogs in more detail, and outline what causes it, and whether or not lactose is actually dangerous to dogs. Read on to learn more.

Dogs and dairy products

While we think of lactose intolerance as being something faced by people as a rule, dogs can be lactose intolerant too, and it is actually rather more common in dogs than people; with some schools of thought indicating that there’s a reasonable chance that all dogs are lactose intolerant to a degree.

Other than the milk produced by their own dams when they were pups, milk and other dairy products aren’t something that dogs in the wild and throughout history would have eaten. Doges evolved as hunter-scavengers, and milk isn’t something they’d have happened upon; and other dairy products are processed goods made from milk, again not making it into the canine diet.

It is only since dogs became domesticated, and began to scavenge and be fed scraps from humans, that any form of dairy made it into their diets; and lactose certainly doesn’t agree with all dogs.

Dogs don’t tend to produce very much of the lactase enzyme that digests lactose; which is likely because evolution has never really required them to have it, as dairy products weren’t part of the canine diet.

Dogs can suffer from lactose intolerance just like people can, and as is the case for people, how badly they suffer from it and how bad the symptoms it causes are can vary from dog to dog. One dog might be able to eat a lot of dairy products with no problems, and another might get an upset stomach from just a small quantity of milk or cheese.

What is lactose?

Lactose is basically a type of sugar that is found in milk and so, products made from milk – we tend to think of lactose as pertaining to cow’s milk, but it is found in all other types of animal milk too, although to different degrees.

Cow’s milk is higher in lactose than most other types of milk; which is why some people that cannot have cow’s milk due to the presence of lactose can have products made from sheep, goat, and other types of milk.

What is lactose intolerance?

Lactose intolerance is the name given to a condition in which the body doesn’t produce enough of an enzyme called lactase, which is required to effectively digest lactose. Lactose intolerance means that eating a product that contains lactose renders it indigestible to a degree, which can be variable.

This tends to result in digestive discomfort and potential upset from eating or drinking dairy products or something containing lactose, including bloating, and potentially diarrhoea, all of which can be uncomfortable.

Is lactose dangerous to dogs?

Lactose is not dangerous to dogs per se, as even in dogs that are lactose intolerant, the substance isn’t toxic to them; rather, just indigestible. The potential digestive symptoms that accompany eating lactose if this doesn’t agree with the dog can be uncomfortable and result in diarrhoea, but this is usually as bad as it will get.

In very rare cases, a dog might potentially have an acute allergy to lactose or another element in dairy products, causing a far more serious problem, but this is not the same thing as lactose intolerance in dogs.

However, while lactose isn’t poisonous to dogs, a reasonable number of them will get digestive discomfort from eating something containing lactose, and if their intolerance is only mild, you may not even be aware of this. Also, there’s nothing specifically in dairy products that dogs need in their diet that cannot instead be supplied from another source in normal dog food of a balanced dog-appropriate diet.

Dairy products as a whole, like milk and cheese, are also generally quite high calorie, and cheese is very fatty too. Some forms of yoghurt can be beneficial for dogs to support digestive health, but this does again rely on the dog being able to tolerate ingestion of them.

There’s no real value nutritionally to lactose products for dogs, and they shouldn’t generally be fed deliberately as treats. But if your dog did happen to drink milk, eat cheese, or otherwise consume some form of dairy products, this in and of itself won’t harm them, even if it does not really agree with them either.

Newsletter icon
Get free tips and resources delivered directly to your inbox.


Pets for StudWanted Pets

Accessories & services


Knowledge Hub


Support & Safety Portal
All Pets for Sale