Can Dogs Have Soy Milk?

Yes, dogs can have soy milk but it’s not recommended as a regular part of their diet. While not toxic, it could cause digestive upset in some dogs depending on their individual tolerance.

It’s also important to note that some brands of soy milk may contain additional ingredients such as sugars and flavorings that are unhealthy for dogs. A high amount of these could potentially lead to unwanted weight gain and even diabetes.

In general, moderation is the key when giving human foods to your canine companions. If you choose to give your dog soy milk, it should only be as an occasional treat, and not a substitution for their regular dog food or water.

If you notice any signs of digestive upset or allergic reaction after giving soy milk, like diarrhea or excessive scratching, you should stop giving it and consult with a veterinarian.

Last Updated on September 20, 2023

Milk is nutritious and good for you. But not everyone can take dairy products. (That includes me — I have to say no to milk or the creamiest cheeses, sigh!) Those of us who are lactose-intolerant must use non-dairy substitutes, like soy milk.

But dogs can be lactose-intolerant, too. Can dogs have soy milk? Is it safe for them?

can dogs have soy milk
Yes, most dogs can drink soy milk, but only in moderation. And some dogs are allergic to it or get an upset stomach from it.

Soy milk is good…

If you only want to boost the nutrition in your dog’s diet but are having problems with his lactose intolerance then, yes, soy milk is safe for your dog to drink or have in their food.

Soy milk is made from soybeans that have been soaked in water overnight, ground up, boiled, then separated or filtered out. The white liquid that is extruded is the soy milk; the curds make tofu.

The entire production process of soy milk ensures it is both hygienic and nutritious. Heating the soy milk boosts its taste and its nutritional value, making it an excellent substitute for cow’s milk.

can dogs have soy milk
The best and safest soy milk (for both you and your dog) is unsweetened and comes without any additives. If you can’t get this, you can make your own soy milk. Photo by: LinasD, May 2010, Wikimedia Commons.

But only in moderation!

However, soy milk is best for dogs only in moderation. (How much is enough? More on that, later!) There are also a few brands of soy milk out there that could be harmful to dogs, especially when taken in large quantities.

Here’s why:

1. Harmful additives

In East and Southeast Asian countries where soybeans are a part of everyday cuisine, a lot of soy milk sold in supermarkets and street stands tends to be freshly-made and all-natural — no sugars, artificial sweeteners, flavors, or preservatives added. It’s appreciated as a beverage in its own right and isn’t treated as a milk substitute.

However, in Western countries where people aren’t used to its taste, soy milk tends to be thickened, sweetened, and flavored with all sorts of additives, either natural or artificial. It also comes with added preservatives for a longer shelf life.

A few examples of what could be added to soy milk are:

  • Artificial flavors and coloring – vanilla, strawberry, banana, chocolate, cookies ‘n’ cream, etc.
  • Artificial sweeteners – advantame, aspartame, saccharin, sucralose, xylitol, neotame, etc.
  • Preservatives – potassium metabisulphite (KMS), potassium sorbate, and sodium benzoate
  • Thickening agents – edible oils, gelatin, carrageenan

The trouble with some of these additives (especially the artificial ones) is that they can cause harmful side effects or even death in dogs. Here are a few examples:

  • Xylitol, for instance, is an artificial sweetener that’s poisonous to dogs. The smallest amount can kill them. While xylitol is used mostly in chewing gum, candies, peanut butter, and toothpaste, you must always be on the lookout for it in other food items you buy, in case you accidentally let your dog nibble on something sweetened with it.
  • Carrageenan is a thickening agent derived from seaweed and is used in commercial food products, including some soy milk brands. This ingredient can sometimes irritate the gastrointestinal tracts of some dogs (and people!).
  • Some preservatives, artificial flavors, and colors are made by third parties that soy milk manufacturers buy their supplies from. So they don’t directly control how safe these are. These compounds might even be imported from other countries with lax regulations on the manufacturing of such products — so it’s possible some of these might be carcinogenic enough to cause long-term harm to dogs.
  • Lots of times, soy milk is flavored with natural chocolate. Chocolate is poisonous for dogs.

To avoid all of this, it’s safest to buy unflavored traditional soy milk from specialty shops and Asian supermarkets or to make your own. (Again, more on that later.)

2. Oil and sugar = Extra calories

Traditionally, soy milk is made and consumed as is. But commercial soy milk manufacturers also add in lots of sugar or edible oil to sweeten or balance out the flavor and texture of their product.

Sugar has carbohydrates and oil contains fats, both of which provide extra caloric value to the soy milk. However, if your dog doesn’t need those extra calories (since his main diet should be providing most of it), giving him this sort of soy milk could lead to unwanted weight gain.

3. Possible allergy trigger

Soybeans, tofu, and soy are among the top food allergens among dogs. If your dog already has allergies to other ingredients, soy milk might not be for him.

4. Isoflavones

Soy is rich in isoflavones, compounds that are similar to estrogen.

Estrogen is a hormone present in both humans and dogs which regulates many body functions, including how the thyroid controls metabolism and how the reproductive system operates. But when there’s an abundance of isoflavones coming from what a dog eats or drinks, it could throw some of these functions out of whack.

Some studies even suggest that an overdose of isoflavones can promote the growth of certain types of cancer cells.

The nutritional benefits of soy milk

Nevertheless, soy milk is nutritious and worth adding to your dog’s diet — if you do it in moderation and use only plain soy milk.

Unsweetened soy milk is already mildly sweet and has about 80 calories per cup. One cup also contains the following nutrients:

  • 4 grams of fat
  • 3 grams of carbohydrates
  • 3 grams of dietary fiber
  • 1 gram of natural sugar (inherent to the soybean)
  • 7 grams of protein

Soy milk’s natural oil-to-protein ratio is lower than cow’s milk. So while it provides nearly as much protein, it’s lower in fat.

A moderate amount

A moderate amount of natural unsweetened soy milk for a dog would be (depending on the size of the dog) about one to two cups per week, spaced out across several days.

If you’ve got a small dog, keep it at no more than one cup a week. A larger dog can go to two cups.

Note: Serve soy milk only to adult dogs. If you’ve got a puppy, don’t ever replace their mother’s milk or puppy milk formula with soy milk. Puppies need those more nutrient-dense and fatty types of milk to grow and develop. You will be undernourishing them if you switch to soy milk.

How to start

If you’re never served soy milk to your dog before and are nervous about introducing it into his diet, start with about half a cup and see how he reacts. Observe how he likes it, how he behaves and feels afterward, and how he poops later on.

You will know if a dog has soy milk allergies if he displays the following symptoms:

  • Upset stomach and diarrhea
  • Vomiting
  • Itching and excess licking of body parts
  • Ear infections

But if all seems normal, you can raise the amount you give per week.

can dogs have soy milk
Here’s another serving idea: mix soy milk with your dog’s dry dog food or cereal.

Soy milk recipes

Can’t find unsweetened soy milk in your area that’s safe for your dog and delicious to your taste? Don’t know how else to incorporate soy milk into your dog’s diet? Here are a few recipes to try.

Homemade soy milk

You can purchase dried soybeans from a specialty shop or grocery, soak them in water overnight, boil them, then strain the milk out.

(Click here for a more detailed recipe and process for making soy milk.)

Dog soy milk biscuits

You can also bake homemade doggie biscuits with soy milk. Use dog-safe ingredients like whole wheat flour, unflavored rolled oats, honey, and peanut butter (as long as it doesn’t contain xylitol!).

(Click here for a more detailed recipe.)


So yes, dogs can have soy milk in moderation. If it’s your first time to try soy milk — for yourself and your dog! — and feel a bit iffy about it, think of it as a great culinary and nutritional experiment. It’ll be a delicious experience you and your baby can share.

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