Can Cats Drink Milk?

We’ve all seen it, whether in a cartoon, childhood story, depicted on the big screen, or a watercolor illustration: cats drinking milk. It seems as natural a look to a cat as, say, a dog chewing a bone. But, do these fictional depictions carry any weight in real life? Turns out, that while some cats go crazy for a lap of milk, this dairy beverage may be the last thing they need. So, we wanted to ask, can cats drink milk?

The Short Answer

“The easy answer is no, as kittens grow up into cats, intestinal lactase (the enzyme catalyzing lactose digestion) decreases to a fraction of that found in kittens,” explains Dr. Ann Hohenenhaus at The Animal Medical Center in NYC.

So, as a cat ages, the lower their lactase levels become, the harder it is for them to digest lactose. This actually results in most grown cats becoming lactose intolerant. “If they drink milk, they can develop diarrhea or have vomiting due to this intolerance. Usually you will see those signs in 8-12 hours,” shares Dr. Stephanie Liff, DVM and partner at Brooklyn Cares Veterinary Hospital.

The Facts Behind It

The milk we drink and the milk that cat’s produce are different. “Lactose is the carbohydrate found in milk, cow and goat milk have more lactose than cat milk does,” says Dr. Hohenenhaus. “Feeding cow or goat milk to kittens, even with their high levels of lactase, may cause diarrhea from the inability to digest the high levels of lactose found in cow or goat milk.”

A Better Substitute

Sharing a tablespoon or two of the milk you drink with your cat may not negatively affect his tummy, but as Dr. Liff explains, there are no health benefits. “To let your favorite kitty have the milk they desire, consider cat milk, which is really lactose free milk with added taurine, an essential vitamin for cats,” says Dr. Hohenenhaus. That being said, “Keep in mind that cat milk should be considered a treat, as it contains calories.” Veterinary nutritionists recommend no more than ten percent of your cat’s daily calorie allowance come from cat treats, so you should check with your veterinarian about exactly how much cat milk your cat can have each day, recommends Dr. Hohenenhaus.

If you’re nursing a kitten that was separated from its mother too soon, kitten milk replacers can help them ingest the extra calories they need and can be bought at most pet stores. “Cow milk has casein and whey proteins that kittens usually struggle to digest, but kitten milk replacers are balanced more appropriately to be as close to cats milk as possible,” says Dr. Liff.

The Best Option

So if you decide to give your cat some milk as a treat every now and then – assuming their stomachs can handle it – don’t skimp on keeping their water bowl full. H20 is an essential part of your cat’s daily diet, “Water is much more important for digestion and health, so any treat, including milk, should not replace water,” says Dr. Liff.

Image: Olesya Kuznetsova via Shutterstock

Caitlin Ultimo is a writer & editor for PetMD her work specializes in pet, family & beauty writing.