Cats are carnivores. That's the most important thing to keep in mind when considering what to feed yours.
"Cats are… different from us and from dogs," says Louise Murray, DVM, vice president of the ASPCA's Bergh Memorial Animal Hospital in New York. "When it comes to nutrition, they are very inflexible, and owners must realize that."
Compared to what their owners should be eating, cats need to eat a lot of meat for protein and for fat.
"If we ate like cats, we'd have heart disease by age 20," Murray says. "They are not at all the same as humans and they are not little dogs."
She's explicit about this because it's not uncommon for owners to treat their cats the same way they treat dogs, which can eat a variety of foods and remain healthy.
In fact, Murray notes that dog food can be fatal to cats over time because it doesn't meet their nutritional needs and it's often loaded with carbohydrates, which cats can't process well.
"Cats get severe obesity problems from carbs, which can lead to diabetes," Murray says. "A cat's system is not designed for carbs. They are to be avoided."
When choosing a cat food, check that the label says it meets the standards set by the American Association of Feed Control Officials (AAFCO). That ensures that the food meets at least the minimum nutritional needs of your cat.
You can ignore terms like "gourmet," "premium," "super-premium," and "natural," which have no standard definition.
You can ask your vet what type of food (wet or dry) they recommend for your cat.
Once you've made your choice, let your cat do a taste test. If your cat likes the food and doesn't have any gastrointestinal upsets (such as diarrhea) afterward, you've chosen well.
However, if your cat doesn't like the food, you need to be prepared to offer options. Cats often will go on hunger strikes rather than eat something they don't like, says Murray, and such strikes are dangerous.
"A cat that won't eat can suffer from liver failure and get fatally ill," she says. "They can get themselves into big trouble."
If you do need to switch from one food to another, introduce the new food gradually, in small amounts over a week. This helps prevent your cat from rejecting the new food outright and lessens the risk of upsetting your kitty's stomach.