Is it Ok for Cats to Drink Milk?

Where did the idea come from, of cats drinking milk? Think about it logically. In the wild, a cat isn’t realistically going to have access to a cow’s udder. At what point did humans decide it was a good idea to put down a saucer of milk for their cat to enjoy?

Milk is a food for young animals before they are weaned, and whilst some adult cats get away with drinking milk, it’s not really a good idea. Indeed, the majority of cats are milk-intolerant, largely due to the milk sugar, lactose. Fresh, clean water is all a cat really needs to stay healthy and hydrated.

Kittens and Milk

A mother cat’s milk is extremely nourishing to her kittens. Their first milky drink contains a substance called colostrum, which is rich in vital antibodies which act as a security blanket against infection. Mother’s milk is perfectly balanced for kittens, and milk sugars provide a valuable source of energy.

However, over time most kittens stop producing the enzyme (lactase) necessary to break up milk sugars. This is especially likely once the kitten is weaned and taking solid foods.

Even giving cow’s milk to a kitten is risky. Whereas an adult cat can cope with the inconvenience of a stomach upset, diarrhoea in a kitten quickly makes them dehydrated with potentially life-threatening consequences. Unfortunately, if you need to hand-raise a kitten then there’s no substitute for mother’s milk. . . but luckily you can purchase ‘cat formula’ powered milk from your vet clinic or pet store.

Lactose, Lactase, and Casein

Cows’ milk contains a sugar called lactose, which needs a gut enzyme called lactase to break it down into smaller molecules that are able to pass across the bowel wall. The problem is that most cats lack the enzyme lactase.

This means milk sugar can’t pass across the gut wall into the blood stream and stays trapped in the bowel. Bacteria then get to work, and feel obliged to turn the milk into yogurt by fermentation. The lactose also draws in water, with the net result of a flatulent kitty with stomach cramps and diarrhoea.

To make matters worse, some cats are also intolerant to the milk protein, casein. In the same way a dietary allergy to beef, lamb, or rabbit causes the lining of the bowel to become inflamed, so can casein. And the result. . . you guessed it — stomach upsets and diarrhoea.

What about the Alternatives?

The first thing to say is that cats don’t need milk. In much the same way we eat chocolate because it tastes nice, cats drink milk. But even if it doesn’t upset their tummy, there’s an argument that it loads them up with calories and replaces food that provides extra vitamins and minerals.

What would you guess is the equivalent in calories to a person, of a saucer of milk to a cat?

It may surprise you to find out that a simple saucer of milk provides around the same calories to a cat as four burgers for an average-sized woman. Now it’s not so hard to see why milk shouldn’t be offered lightly.

But if you still feel the overwhelming need to give your cat a treat, what about the alternatives?

Cat Milk

Those clever pet food manufacturers know we like to spoil our feline friends and so they invented cat milk. This is actually cow’s milk with the lactose taken out. Whiskas make a lactose-free milk marketed as cat-milk, whilst there are human equivalents such as Zymil which is pretty much the same but targeted at the human market.

The majority of cats can drink this without problems, unless they are intolerant of casein! However, think calories, calories, calories, and ask yourself if that moment on the lips is worth a life-time on your cat’s hips.

Also, just because it says “Cat” on the label, doesn’t mean it’s suitable for rearing kittens. It just doesn’t contain the right balance of proteins, minerals, and vitamins for a growing cat. Think about raising a human baby on chocolate and you get the picture.

Goat’s Milk

Goat’s milk has good press in nutritional terms, and is considered relatively easy to digest. However, goat’s milk still contains lactose. . .just less of it.

So why do some cats that can’t drink cow’s milk do better with goat’s milk? This is because the latter contains a lot less casein. Thus these cats are probably OK at digesting lactose but are casein intolerant, and so are able to digest goat’s milk but not cow’s.

Soy Milk

If you were hoping for better news with soy milk, then you’re about to be disappointed. Soy milk is often sweetened with cane sugars, which cats find hard to digest. Indeed the presence of stachyrose and raffinose mean they are liable to ferment in the cat’s gut, making it just as problematic as cow’s milk even though soy is low in lactose.

Think of the effect of feeding tins of baked beans to your cat and you get some idea of the resulting flatulence and potential for tummy upsets that soy milk can cause cats.

What about Dairy Products?

Some cats that can’t tolerate milk are OK licking out a yogurt pot or with the occasional nibble of cheese. Why is this?

This is down to dairy products being adulterated with fats or even water. This dilutes the lactose component and since the digestive upset is usually proportional to the amount of lactose eaten, it means ice-cream, butter, or yogurt can sometimes creep in under the threshold that causes an explosion.

What about My Cat?

If you want to know if your cat can tolerate dairy or milk, and are prepared to cope with a stomach upset, then try them with a couple of desert spoons of milk and wait a couple of days to see what the result is.

However, before regularly giving your cat milk know that:

• Milk is highly calorific to cats
• Cats don’t need to drink milk to be healthy
• The quantity of lactose is proportional to the size of the stomach upset. The bigger the saucer the more voluminous the resulting output!
• Keep treats to less that 5 – 10 % of your cat’s total calorie intact, or you may rob your cat of essential nutrients.

In short, as a responsible cat guardian you need to weigh up whether it’s really worth giving milk to your cat even if they can tolerate it. Instead of milk beverages, we recommend making sure your cat has a bowl of fresh, clean water readily available at all times.