Are Dogs Lactose Intolerant?

By Chyrle Bonk, DVM March 12, 2020

Sharing our favorite ice cream cone on a hot summer day or some hot cocoa in the winter with our dog has probably crossed every dog parents’ minds.  Since it’s so hard to resist those begging puppy-dog eyes, some dog parents might of surrendered and gave their pup a taste. But before you share even just one lick or sip, think a little bit about lactose intolerance and if your dog could be affected.

What Is Lactose Intolerance?

Milk is jam packed with lots of healthy nutrients-calcium, protein, and vitamins to name a few. It also contains a sugar called lactose. Lactose requires a specific enzyme called lactase to break it into smaller digestible pieces. Without lactase, lactose can’t be properly broken down and can lead to digestive issues. Puppies produce lactase by the tummy full in order to fully reap the benefits of their mother’s milk. After weaning, lactase production drops to the point that only small amounts of milk can be consumed at a time without digestive upset.

Are Dogs Lactose Intolerant?

With the drop in lactase production caused by weaning, and the fact that cow’s milk is even higher in lactose than a mama dog’s milk, most adult dogs are lactose intolerant. However, that doesn’t mean that dairy products are completely off limits for our pups.

What Are The Signs Of Lactose Intolerance In Dogs?

There are varying degrees of lactose intolerance in dogs, producing varying degrees of symptoms. The degree of symptoms can also depend on the amount of milk that was consumed. Dogs with lactose intolerance may display the following signs:

  • Diarrhea

By far the most common sign of lactose intolerance is diarrhea. The diarrhea may show up as loose or watery stools or be full-on explosive.

  • Vomiting

The first instinct of a dog’s stomach is to get something unfavorable out. In the case of lactose intolerant dogs, they may try to vomit out any dairy products before it reaches the rest of the digestive tract.

  • Gas and bloating

Gas is a normal byproduct of digestion. It means that food is being broken down and fermented properly. However, lactose intolerance in dogs can mean more gas production than normal. Sometimes the gas becomes trapped and causes bloating.

  • Abdominal pain

Bloating and excess gas can be very uncomfortable. We’ve all been there. To say you feel like a balloon that’s about to pop is an understatement. Your dog feels the same way after consuming milk when they’re lactose intolerant.

  • Decrease in appetite

When a digestive system is going through diarrhea, vomiting, and bloating, most of the time it doesn’t want additional food to process. So, most dogs that are lactose intolerant will stop or slow down their eating in order to give their digestive system a break.

What Happens If A Dog Drinks Milk?

Most of the time, even in lactose intolerant dogs, a few laps or tablespoons of milk aren’t going to cause any problems. However, if your pup drinks a couple cups of milk or is extremely lactose intolerant, you could be dealing with a sick pup for a while. As we said before, lactose needs lactase enzyme to break it into small digestible pieces. Without lactase, lactose is too large to be absorbed and will travel through the digestive tract as one big molecule. Once it reaches the colon, the body tries to dilute it out by dumping large amounts of water into the digestive tract. This is what creates the watery stools or diarrhea. That is unless your dog has already vomited the milk up.

On top of that, the high amounts of fat in milk may also cause vomiting and diarrhea, or even pancreatitis, on their own right.

Can Dogs Have Lactose Free Milk?

Don’t confuse lactose intolerance in dogs with a true milk allergy, even though some of the signs and symptoms may be the same. A milk allergy may be caused by the protein, fat, or other components of the milk, and you may see a problem in your pup when fed any of these ingredients on their own. Depending on what part of the milk your dog is adverse to, lactose-free milk may create the same problems as regular milk.

Should You Let Your Dog Have Dairy Products?

With all the digestive unpleasantness that can come with dogs eating dairy, you might be thinking no dairy, no way. But let’s not forget all of the other healthy nutrients that dairy products provide as well. Also, don’t forget that not all dairy products are equal in the amount of lactose that they contain. Milk, of course, reigns as king when it comes to lactose content. However, cheeses and yogurt contain far less lactose, making them safer for some lactose intolerant canines.

Consider giving your pup dairy products as treat or sometimes for illnesses. A small cube of cheese makes a great pill hider, and yogurt contains a lot of beneficial probiotics that can actually increase gut health rather than hinder it. Cottage cheese is a great source of calcium for unfortunate critters with broken bones. Dairy products can add lots of benefits to a dog’s diet, you just need to feed them in small amounts and discontinue if you suspect an allergy. Most lactose intolerant dogs can handle a couple tablespoons of milk or ice cream, so if a treat is in order, that may be an option.

However, don’t feed dairy to you a pup with a dairy allergy. While the signs of a dairy allergy and lactose intolerance can sometime overlap, dairy allergies will be far more severe. Meaning even tiny amounts of milk or other products can produce massive diarrhea and vomiting events. A dog with a milk allergy may also turn up with hives or swelling of the face, skin itchiness or a rash, or even shortness of breath. For these dogs, dairy in any form is usually a no-go.

What Should You Do If Your Dog Drinks Milk?

For lactose intolerant dogs, drinking a little too much milk or eating a bit too much dairy products will usually produce digestive signs within 12 hours. There isn’t much you can do except wait it out and be supportive. Offer small amounts of food and water frequently to not overwhelm the stomach with one big meal. Going out for a walk can sometimes relieve bloating and gas. If your dog’s discomfort or vomiting and diarrhea is severe, see your veterinarian.

For dogs with food allergies, drinking milk can be a totally different thing. See your veterinarian if your dog shows signs of hives, swellings, or a shortness of breath after eating dairy.

Is Milk Good or Bad For Dogs?

Let’s get to the bottom line, should dogs drink milk or not? The quick answer is not cow’s milk and not any milk after weaning. While other dairy products, like yogurt and some cheese can be tolerated by a lactose intolerant dog, milk just ranks too high in lactose content. Your dog should be able to get the nutrients found in milk from other sources, so there is really no reason to risk the digestive repercussions of feeding your dog milk.


Lactose intolerance in dogs is a common issue that affects nearly every one of our canine companions. Even though puppies survive solely on milk for the first several weeks of life, after weaning their digestive systems evolve to where they can’t tolerate more than a small amount. Some dogs even develop allergies to some components of milk that makes small amounts off limits. With this in mind, it’s best to keep milk out of your dog’s dish. But, that doesn’t mean all dairy products. Yogurt and some cheeses can have a place in your dog’s diet if used in moderation. So try to resist the urge to share your ice cream and milk with your pup. Instead give them lots of love and attention.

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