Why Can Kittens Drink Milk, but Adult Cats May Not?

This is where things can get confusing. After kittens are born, they rely on their mother’s milk for essential nutrients. Because milk contains lactose, kittens naturally produce an enzyme called lactase, which helps them digest it.

But as kittens gradually wean and start eating solid food, lactase activity typically decreases. In other words: Kittens drinking their mother’s milk ≠ adult cats needing cow’s milk.

This is a natural part of their development. And cow’s milk is not the same as a mother cat’s milk, either. So just because kittens need milk during early development doesn’t mean adult cats need milk as part of their everyday diet.

What Happens If an Adult Cat Drinks Milk?

If a cat cannot properly digest lactose, the undigested lactose can move into the intestines, where it may be fermented by gut bacteria. This can lead to digestive discomfort.

Possible signs include:

• Soft stool or diarrhea
• Gas or bloating
• Abdominal discomfort
• Vomiting
• Stomach gurgling or noticeable digestive discomfort

Every cat is different, and their tolerance can vary. Some cats may drink a small amount without showing any obvious reaction, while others may develop digestive symptoms fairly quickly. So, just because “my cat drank milk and was fine” doesn’t mean “all cats can drink milk.”

“But My Cat LOVES Milk!” What Should I Do?

This is a common question from cat parents. The answer is: Liking something doesn’t necessarily mean it’s good for them.

Cats may enjoy the taste, fat, or texture of milk, which can make them eager to sneak a sip from your glass. But just because they like something doesn’t mean it’s the best choice for their everyday diet.

It’s similar to how dogs may be extremely interested in whatever is on your dinner table. They might think it smells delicious, but as pet parents, we still need to help them make healthier choices.

What Do Cats Really Need? Water!

If your goal is to help your cat get more fluids, milk is not the best solution.

Water is the most important source of everyday hydration for cats.

Cats may naturally have less obvious drinking habits than dogs, and some cats simply don't drink very much on their own. Instead of trying to convince your cat to “drink more milk,” try finding ways to make getting enough water easier and more appealing. Here are a few things you can try.

Method 1: Add More Water to Their Food

If your cat enjoys wet food, it can be a great way to increase their daily water intake. Canned food, complete-and-balanced wet meals, or other high-moisture foods can all contribute to their daily hydration. For cats that aren't big fans of drinking water: The water they eat still counts toward hydration.

You can also try adding a small amount of water to food your cat already enjoys and gradually increase it if they accept the change. Every cat is different, so start with a small amount to avoid suddenly changing the taste or texture of their food.

Method 2: Try a Pet-Safe Broth Without Onion or Garlic

Some cats aren't very interested in plain water but become very interested when something smells delicious.

In that case, you can consider using a simple, pet-safe broth specifically formulated for cats as an addition to their regular diet.

But there's one important rule:

❌ Don't give your cat human chicken broth or soup.

Human broths, soups, and seasonings may contain ingredients that aren't appropriate for cats, including:

• Onion
• Garlic
• High amounts of sodium
• Other seasonings that may be unsuitable for cats

So whenever you choose a broth, always check the ingredient list carefully.

Method 3: Use a Wet Food Topper

If your cat isn't particularly interested in drinking water, try combining hydration with something they already love.

For example:

Wet food + a little water

Wet food + pet-safe broth

Wet food + a cat-friendly topper

This way, you don't have to force your cat to “go drink water.” Instead, you can incorporate additional moisture into food they're already comfortable eating.

For picky cats: “Drink some water” may not sound very exciting, but “eat something delicious” can be much more convincing. 

What About Goat Milk?

This is another question many cat parents ask. “If regular milk isn't ideal, is goat milk better?”

The answer is: Goat milk isn't completely lactose-free.

Goat milk still contains lactose, so cats that have difficulty digesting lactose may still experience digestive discomfort after drinking it. Some pet-specific goat milk products are specially processed, such as having reduced lactose levels, which may make them easier for some cats to tolerate.

However: Don't use regular goat milk as a replacement for your cat's everyday drinking water.

If you want to try goat milk, choose a product specifically formulated for cats and start with a small amount. If your cat has an existing digestive issue, it's best to check with your veterinarian first.

What Should I Do If My Cat Feels Sick After Drinking Milk?

If your cat develops any of the following after drinking milk:

• Diarrhea
• Persistent vomiting
• Obvious abdominal pain
• Low energy or lethargy
• Decreased appetite

Don't keep giving them milk to “see if they'll get used to it.” Stop offering the milk and monitor their symptoms. If symptoms are severe, persistent, or accompanied by other unusual signs, contact your veterinarian.

This is especially important for kittens, senior cats, or cats with existing health conditions. Milk should never be used as a substitute for their normal food or water without veterinary guidance.

So, Can Cats Drink Milk?

Here's a quick summary:

The Next Time Your Cat Tries to Steal Your Milk...

Give them a little head scratch and tell them: “I know you really want some, but I have something better for you!” 

Milk may be the classic “cat drink” we remember from cartoons and childhood stories, but for adult cats, water is the truly important everyday beverage. The next time you're tempted to pour your cat a little saucer of milk, try adding some extra moisture to food they already enjoy instead.

For cats who enjoy different textures, check out Get Naked® Soft Treats and Get Naked® Crunchy Treats. From soft and chewy to satisfyingly crunchy, these treats can be an easy way to add a little variety to your cat's daily routine.

After all, taking care of our pets isn't just about giving them what they want, it's about helping them choose what is truly right for them.