Is It Okay to Give Cats Milk? What Actually Happens When You Treat Your Cat to Dairy, and What to Offer Instead

Let’s clear up the myths with facts, science, and a little help from veterinary experts

For generations, the image of a contented cat lapping up a saucer of milk has been a fixture in children’s books, vintage ads, and classic cartoons. Many of us who grew up in the ‘70s and ‘80s remember treating our cats to a splash of milk with the best of intentions. But in reality, is it actually okay to give cats milk?

The short answer: not really—at least not the kind of milk you likely keep in your fridge. The longer answer? It depends on the type of milk, the age of your cat, and how much you’re offering.

Why Cats Like Milk—Even If It Doesn’t Like Them Back

Cats are naturally attracted to the rich smell and fatty texture of dairy. That creamy texture mimics the fat content found in animal prey—especially appealing to obligate carnivores like cats. But many adult cats are actually lactose intolerant.

As kittens, they produce an enzyme called lactase, which breaks down lactose, the sugar in milk. However, most cats lose this ability after they are weaned around 8–10 weeks old. That means when adult cats drink regular milk, they can’t properly digest it—and it ferments in their gut, often causing:

• Diarrhea

• Gas

• Stomach cramps

• Bloating

As Cornell University's College of Veterinary Medicine notes, feeding adult cats milk provides no nutritional benefit and often causes gastrointestinal upset.

Can Cats Drink Lactose-Free Milk?

Yes—in very small amounts, lactose-free cow’s milk is generally safe for cats. It doesn’t contain the sugar that most cats struggle to digest. But just because it's tolerated doesn't mean it's needed.

Lactose-free milk still contains fat, protein, and calories, so it’s best treated as an occasional indulgence—not a daily drink.

If your cat really enjoys a milky treat, a teaspoon or two once a week is generally fine. But keep in mind that a typical indoor cat only needs about 200–250 calories per day, and even small servings of milk can add 20–40 unnecessary calories.

What’s in Commercial “Cat Milk” Products?

If you’ve walked through the pet aisle lately, you may have seen small cartons labeled “cat milk.” These are formulated specifically for adult cats and are different from both cow’s milk and kitten formula.

Most brands, like Whiskas Cat Milk or CatSip, are:

• Lactose-free

• Lower in fat

• Fortified with taurine, a vital amino acid that supports vision and heart health in cats

• Free of additives that can upset a cat’s digestive system

They’re a safer alternative than milk from your fridge—but still best given in moderation. The American Society for the Prevention of Cruelty to Animals (ASPCA) advises that treats, including milk alternatives, should make up no more than 10% of a cat’s daily caloric intake.

Is Kitten Formula the Same as Cat Milk?

Not at all.

Kitten Milk Replacer (KMR) is a high-fat, high-protein formula designed to mimic a mother cat’s milk. It’s meant only for orphaned or nursing kittens who can’t get enough nutrition from their mother.

Brands like PetAg KMR or Breeder’s Edge are commonly used by shelters and foster caregivers. Adult cats don’t need these products—and because they’re so rich, they may even cause loose stool or upset stomachs in grown cats.

When a friend of mine tried using leftover KMR to “bulk up” her adult rescue cat, the result was a week of litter box trouble and a trip to the vet. Lesson learned.

How Much “Safe” Milk Can You Give a Cat?

If you’re offering lactose-free cow’s milk or a commercial cat milk, stick to:

• 1 to 2 teaspoons per serving

• No more than once or twice per week

• Only if your cat tolerates it well

Always watch for signs of sensitivity—such as soft stools or a bloated belly—and stop immediately if symptoms appear.

And no, milk is not a replacement for water. According to the American Veterinary Medical Association (AVMA), fresh, clean water should be your cat’s primary drink—changed daily and always available.

Do Kittens Need Milk Once They’re Eating Solid Food?

No. Once a kitten is about 8 weeks old, their digestive system is ready for solid food—and they no longer need milk of any kind.

PetMD recommends feeding high-quality wet or dry kitten food after weaning. Adding milk at this stage can actually lead to diarrhea, which is especially dangerous for young cats.

Alternatives to Milk for Cats Who Like Creamy Treats

If your cat seems obsessed with milky textures, try offering:

• A spoon of unsalted bone broth (no onions or garlic)

• A dab of plain Greek yogurt (some cats tolerate fermented dairy better—just check ingredients)

• Water with a splash of tuna juice for flavor

One of my cats, a tabby named Penny, used to chase me every time I opened a yogurt cup. After a few tummy troubles, I found that offering her a teaspoon of Whiskas Cat Milk once a week gave her the same satisfaction—without the fallout.

The Bottom Line: Milk Isn’t Necessary—and Often Isn’t Tolerated

Despite the old-fashioned image of cats and saucers of milk, adult cats don’t need milk—and for most, regular cow’s milk will cause more harm than good.

Here’s a quick guide:

✅ Do not give regular milk—most cats are lactose intolerant 

✅ Lactose-free milk or cat milk is okay in moderation 

✅ Kitten formula is for kittens only 

✅ Fresh water should always be available 

✅ Watch for symptoms if trying a new dairy treat

If you want to treat your cat, there are safer and healthier options. But above all, listen to your cat’s body—and talk to your vet if you’re ever unsure.