As pets go, cats are pretty user-friendly: Give them a clean litter box, a sunny windowsill and a scratching post and they’re (mostly) happy. But feeding a feline can be a bit more complicated. Cat owners often make mistakes that can put a kitty’s health at risk, according to Bruce Kornreich, D.V.M., associate director for education and outreach at Cornell University's Feline Health Center. Here are the big ones:

1. Overfeeding. Most cats need just 250 to 300 calories per day. Give your mouser two daily meals instead of leaving a bowl of food out. Either canned or dry food (or a combination) is fine, Kornreich says, as long as the overall diet is nutritionally balanced. Offer treats only occasionally.

2. Letting your cat get fat. According to the American Animal Hospital Association, up to 59 percent of cats (and dogs) are overweight. But if you’re like many pet owners, you may not realize yours is. A chubby kitty can have trouble cleaning herself and may be at risk for problems ranging from diabetes to skin disorders. Your vet will check her weight at her annual check-up. If Tabby tips the scale, the vet can help you develop a feeding plan to lighten her load. Exercise will help too — at least 15 minutes of play each day with a feathered toy, laser pointer or whatever she loves to chase.

cat and weights (Photo: De Jongh Photography/Shutterstock) 

3. Offering milk and tuna. We think cats love them, but their bodies don’t. Cats are lactose intolerant, making dairy a bad idea. Canned tuna presents even more concerns, including high mercury content. Plus, it's not a nutritionally complete food source, and if your kitty gets hooked on it, she may refuse to eat the food that is. An occasional morsel is fine as a treat, but leave it at that.

Related: Introducing a New Cat to Your Home

4. Forgetting to freshen the water bowl. Cats are less likely to lap up water that’s been sitting around or has something in it. Without proper hydration, they can develop urinary problems such as crystals, stones and blockages. Make it a habit to wash and refill the water bowl when you feed your kitty breakfast. cat drinking water (Photo: Phant/Shutterstock)

5. Letting dry food go bad. Dry food is convenient, but when it sits around it can lose some of its nutrients and can even go bad. Store kitty kibble in an airtight container away from light. Dump it once it’s past the expiration date.

6. Ignoring signs of food allergies. Cats can develop sensitivities to proteins, carbohydrates and even fillers in food. If your cat seems uncomfortable and is scratching herself raw, especially around the head and neck, see your vet. She may suggest trying a new protein source (duck! venison!). If that doesn’t help, you may need to see a veterinary dermatologist.

Related: When to Take a Sick Pet to the Vet

7. Serving raw foods. These can expose cats to parasites and bacteria, Kornreich says. Even commercial raw pet foods are more likely to contain bacteria like salmonella and listeria than other types of pet food. If you're set on a raw diet, check out the FDA's advice for safe handling of raw pet food. If you want to feed your cat home-cooked meals, talk with your vet — or ideally, a veterinary nutritionist — to make sure the meals offer the nutrition your pet needs.

8. Making your cat go vegan. Cute as he is, Mittens is a carnivore. Meat provides nutrients that are vital for cats, including vitamins A and B12, taurine and arachidonic acid. If you insist on a meat-free diet for your little tiger, it's crucial to work with your vet to make sure he's getting the nutrients he needs from food and/or supplements. Even commercial vegetarian and vegan cat foods are often nutritionally deficient. 

cat eating food (Photo: Tompet/Shutterstock)