Did you know that cats, like people, can be lactose intolerant? It’s true, and it’s completely normal. Many cats only experience lactose as young kittens in the form of mother’s milk. To properly digest lactose, a cat must have a gene that actively codes for the production of lactase, an enzyme that digests milk sugar. Cats have plenty of lactase at birth, but might lose the ability to produce it as they mature.
If your lactose-intolerant cat drinks milk, the lactose is not digested but passes through the intestinal tract, absorbing water and providing a feast for fermenting bacterial in the colon. The result is the production of volatile fatty acids that can cause your cat to throw up and develop diarrhea. On the other hand, some cats can produce all the lactase they need and have no problem digesting milk.
Test Your Cat
To test if your cat can tolerate lactose, offer it a couple of tablespoons of milk and then look for symptoms to develop within a day. If your cat appears to be lactose intolerant, do not feed it milk. Most veterinarians don’t recommend feeding cow’s milk to cats even if they don’t develop symptoms, because cats don’t need it and it’s not part of the diet of their wild ancestors.
Human foods, such as milk, tuna, cheese and meat, should make up only a tiny portion of your cat’s diet. At least 90 percent of what your kitty eats should consist of cat food that is high quality and nutritionally complete. Your vet can give you guidance on the types and brands to use, and often sells cat food that might not be otherwise locally available. It’s not a great idea to feed your cat table scraps, because they can contain indigestible or dangerous ingredients and may make your cat finicky.
Other Dairy Products
Here’s an interesting fact: even a lactose-intolerant cat might be able to digest yogurt, cheese and other forms of dairy. That’s because many dairy products have little lactose. For example, the lactose in milk is broken down during the making of yogurt by the fermenting microorganisms responsible for the process.
Straight cow’s milk is loaded with lactose, and many healthy cats simply don’t produce enough lactase to adequately handle it. Cow’s milk contains other problem ingredients, including the wrong proportion of casein to whey.
If you adopt a young kitten but don’t have access to mother’s milk, you can use a milk replacement designed specifically for kittens. Your vet can recommend a brand and might even sell milk replacers. These replacement fluids might be made of specially modified cow’s milk in which the lactose has been broken down and the casein-to-whey ratio has been adjusted.
There is also no particular reason to give your cat milk substitutes made for humans, such as lactose-free milk or soy milk. It might be that you inherit a cat that has already developed a taste for these products, but otherwise, your cat doesn’t need them.
Water Is Critical
In terms of liquids, water is much more important than milk. You need to always have plenty of fresh water available for your cat. Use shallow water dishes that are wide enough to avoid touching the cat’s whiskers when it drinks, as cats generally don’t like the sensation. Many cats enjoy kitty water fountains designed just for them. Never let water sit too long and make sure the water bowls are clean before you refill them. If you drink filtered water out of concern for the purity of your local water supply, give your cat the same consideration.
In addition to milk, certain other foods are best not fed to cats, including:
Tuna: highly addictive to a cat’s palate but not nutritionally balanced. Instead, try tuna-flavored cat food, wet or dry, that your vet recommends as completely balanced for your cat’s health.
Chives, onions and garlic: These items can give your cat anemia by breaking down its red blood cells. Also avoid prepared foods that are flavored with onion or garlic powder.
Alcohol: You wouldn’t give alcohol to a baby, and you shouldn’t give any to cats either. Even a little amount can damage their livers and brains, and too much will kill them.
Raisins and grapes: These are clearly hazardous to dogs, but have not been definitively shown to be toxic to cats. It’s best to avoid them to be safe.
Caffeine: This is another potential poison for cats, so avoid coffee, tea, cocoa, chocolate and stimulant drinks.
Xylitol: A sweetener often used in gum and candy, xylitol is toxic to dogs. It is unclear if it presents a risk to cats.
Bone trimmings: Fat and bone scraps from cuts of meat can be harmful. Fat is hard for a cat to digest (cooked and uncooked), and bone fragments can cause choking or internal lacerations.
Raw eggs: There is the danger of E. coli poisoning, plus some cats are sensitive to a protein in egg whites that can interfere with Vitamin B absorption.
The safest way to proceed is to discuss your cat’s nutritional needs with your veterinarian and feed your cat only food made specifically for cats.
Dr. Paul has a strong interest in avian and exotic animal medicine and surgery, as well as small animal internal medicine and surgery.
He has provided services for numerous breeders, kennels, aviaries, and mini zoos.