Leaving Food Out All Day

Your cat might seem like it’s enjoying that constant buffet, but free-feeding is silently destroying their health. Many cat owners make a point to leave a full food bowl out all day, especially if their cat is a picky eater. But it’s better to stop them from grazing. If food is only out at certain times, even the choosiest of cats should eventually eat. Think of it like leaving candy on your desk at work—you’ll definitely eat more than you should. It’s not a good idea to put out a bowl of food and let them graze. This can lead to obesity and other health problems. Your cat needs portion control just like you do when you’re trying to fit into those jeans from five years ago.
Relying Only on Dry Food

The biggest mistake people make is feeding cats dry food, and honestly, it’s shocking how many people don’t realize this. Cats are basically desert creatures who historically got their water from their prey, not from standing puddles. Cats inherently have a low thirst drive and need to consume water *with* their food. (A cat’s normal prey is ~70 – 75% water – not the very low 5-10% found in dry food.) Dry cat food contains around 10% water, and wet food contains around 70% water. Feeding only kibble is like trying to survive on crackers while ignoring your water bottle. The largest benefit of wet food is the amount of water included, which can especially benefit cats with certain health conditions including kidney disease, lower urinary tract disease, and diabetes.
Overdoing the Treats

We get it—those pleading eyes are impossible to resist. But showering your cat with treats is like giving a toddler candy for every meal. Human foods should be given as an occasional treat and shouldn’t make up more than 10% of your cat’s daily calorie intake. Too many treats can throw off their nutritional balance and pack on the pounds faster than you’d expect. Think about it this way: if your cat weighs 10 pounds, that’s like a 150-pound person gaining 15 pounds just from snacks. Not feeding your cat enough can lead to nutrient deficiencies and weight loss, but overfeeding in cats is a much more common problem. Studies show that approximately 61% of cats in the United States are overweight or obese. Those treats might seem harmless, but they add up quicker than credit card debt.
Sharing Your Dinner

Your pasta night might be delicious for you, but it could be deadly for your feline friend. There is a long list of foods that are bad for cats, including chocolate, cream, cheese, grapes and onions. Onions, garlic, shallots, and scallions can cause damage to your cat’s red blood cells and lead to anemia. These foods are typically poisonous when eaten in large quantities, but exposure to concentrated forms of onion or garlic, such as onion soup mix or garlic powder, can also be toxic. Even foods that seem innocent can be problematic. Any food not specifically formulated for cats can affect the digestive system, causing vomiting, diarrhea, or loss of appetite. Your leftover Chinese takeout might taste amazing, but to your cat, it’s basically poison on a plate.
Ignoring Their Carnivore Nature

Some well-meaning owners try to put their cats on vegetarian diets, but this is like forcing a shark to eat seaweed. Cats are obligate carnivores, which means that they rely on nutrients found only in animal products. The amino acid taurine, for example, is found only in animal tissue. Lack of taurine can lead a cat to experienceheart problems, blindness, and even death. Cats also need several specific amino acids to be present – these are taurine, arginine, methionine and cysteine, which are not found in plants. Many animals (including dogs and people) can convert and use other amino acids derived from plants, but cats aren’t able to do this and so, without them in their diet, cats become unwell. Your cat literally can’t survive without meat—it’s not a lifestyle choice, it’s biology.
Giving Them Milk

This one will blow your mind because cartoons have been lying to us for decades. Perhaps surprisingly, dairy products such as milk and cheese are high on the list of what can cats not eat. This is because some cats are lactose intolerant so if they eat dairy products it can cause vomiting and diarrhoea. Cats can become lactose intolerant when they become adults. Their bodies no longer produce enough lactase to digest milk—especially cows’ milk. If ingested by cats, dairy products can cause vomiting and diarrhea. Most adult cats drinking milk will end up with an upset stomach that nobody wants to clean up. It’s like watching someone who’s lactose intolerant demolish a cheese pizza—the outcome is predictable and messy.
Skipping Gradual Food Changes

Imagine if someone suddenly switched your diet from pizza to quinoa salads overnight—your stomach would revolt. Cats are even more sensitive to sudden dietary changes than we are. Gradually decrease the dry, taking about a week to fully switch the cat over to 100 percent canned food. When you need to change their food, you’ve got to be sneaky about it, mixing increasing amounts of the new food with the old over about a week. Think of it like slowly turning down bad music instead of abruptly switching to classical—nobody appreciates jarring transitions. Rushing the process often leads to digestive upset, which means more work for you and discomfort for your cat.
Not Monitoring Water Intake

Cats are notorious for not drinking enough water, which can lead to urinary tract infections and kidney problems. Many owners assume their cat is getting enough water, but cats are basically camels who forgot they need to drink. Some owners assume that wet food provides sufficient hydration, but that’s not always the case. Encouraging your cat to drink water is essential. Consider using a cat water fountain, as cats are often attracted to moving water. All urinary tract systems are much healthier with an appropriate amount of water flowing through them. Your cat might be pickier about their water than you are about your coffee—fresh, clean, and easily accessible should be the standard. Some cats even prefer running water, so a pet fountain might be worth the investment.
Feeding Inappropriate Portions

Eyeballing your cat’s food portions is like guessing your way through a chemistry experiment—the results can be explosive. Probably the most common mistake people make when feeding cats is over-feeding, says Joe Bartges, DVM, PhD, DACVIM, DACVN, professor of medicine and nutrition, the Acree Endowed Chair of Small Animal Research, in the College of Veterinary Medicine, at the University of Tennessee. That’s a question best answered by a professional, though recommendations range between 24 to 35 calories a day per pound, to keep cats at a normal, healthy weight. In general, however, the recommended daily caloric intake is about 20 calories per pound of body weight. For dry food, weighing the food will add less than a couple of minutes to your feeding routine, but could add years to your cat’s life by preventing extra weight gain. Dry food is very energy-dense, so while the correct amount may look small, it provides all the calories your cat needs to stay fit and healthy. Just like human diets, portion control is everything.
Using Low-Quality Food

Not all cat foods are created equal—some are basically the equivalent of fast food for humans. While your wallet might appreciate cheap cat food, your cat’s health definitely won’t. Low-quality foods often contain fillers and artificial additives that offer about as much nutrition as cardboard. Cats have specific nutrient requirements that must be met by their diet. The simplest and most convenient way to meet a cat’s nutrient requirements is to provide them with a complete and balanced commercial diet formulated by a board-certified veterinary nutritionist or an individual with a PhD in animal nutrition. Usually located on the back of the bag or can, this statement indicates whether or not the food is nutritionally complete and balanced for its intended life stage. Foods that aren’t nutritionally complete and balanced will usually be labeled “for supplemental feeding only.” Reading labels isn’t just for paranoid health nuts—it’s essential for responsible pet ownership.
Attempting Raw Diets Without Knowledge

Raw feeding sounds natural and healthy, but doing it wrong is like performing surgery without medical training—dangerous for everyone involved. Just like for humans, consumption of raw eggs or raw meat can lead to salmonella or E. coli poisoning in cats. Symptoms of the illness vary but can include vomiting, diarrhea, and lethargy. Salmonella and E. coli can also be transmitted to humans, so be careful to properly wash your hands after cooking and keep your cat away from these raw foods. Raw foods aren’t always a problem, but feeding raw animal products to cats increases the chances that they will be exposed to pathogens such as salmonella, E. coli, campylobacter, and avian influenza. If you’re determined to go raw, you need professional guidance—not just Google University and wishful thinking.
Ignoring Food Allergies

Some cats are drama queens about everything, but when it comes to food allergies, their complaints are totally valid. Food allergies in cats can manifest as itching, vomiting, or diarrhea, yet many owners dismiss these symptoms as normal feline pickiness. Please consult your veterinarian or a veterinary nutritionist first before adding these foods to your cat’s diet.There is risk of vomiting, diarrhea, Salmonella or E. coli with these foods for some animals, especially when given improperly. If your cat consistently shows signs of digestive upset or skin problems after eating certain foods, they might be trying to tell you something important. Feeding advice may change according to a cat’s lifestyle, health and if they are over- or underweight. Advice in this article may not suit every cat, and advice should be taken from your veterinary team. Just like humans with gluten sensitivity, cats can have legitimate food intolerances that require attention, not dismissal.
Not Maintaining Feeding Schedules

Cats are creatures of habit who thrive on routine more than most people realize. Cats are creatures of habit. We can use this fact to our advantage by creating a regular feeding schedule and sticking to it. Feeding an adult cat at regular times provides the security and predictability of a routine. Your cat shouldn’t go more than 12 hours without a meal. Going too long between feedings causes their stomach to become hyperacidic, which can lead to nausea. In the wild, cats eat frequent small meals throughout the day and night (when their nocturnal prey are active). Feral cats can spend 12+ out of every 24 hours looking for and catching food. Most cats no longer follow their natural meal pattern of eating several small meals throughout the day and night, as they’re reliant on their owners for their food. Often, we feed cats to fit in with our lifestyles – for example, feeding two larger meals during the day. Irregular feeding times can stress out your cat and mess with their digestion—imagine never knowing when your next meal was coming.
What’s most surprising about these feeding mistakes is how common and seemingly innocent they are. Most cat owners genuinely believe they’re doing their best, but good intentions don’t always translate to good outcomes. The key is understanding that cats aren’t small dogs or furry humans—they’re unique creatures with specific needs that have been shaped by millions of years of evolution. Did you realize how many of these “harmless” habits could actually be hurting your furry friend?