9 Foods You Should Never Feed Your Cat

Sharing isn’t always caring. Keep your cat safe by keeping these human snack staples to yourself

18 January 2024

Your cat might have nine lives, but you don’t want to risk them by feeding their voracious appetite. Human foods are one of the top pet toxins. Here, Dr Tina Wismer, DVM, Senior Director of Toxicology for the ASPCA (The US version of the RSPCA) Animal Poison Control Center, shares nine human foods that cats should never eat.

Alcohol

Your cat may act drunk after consuming alcohol, but lack of coordination and drowsiness are not the sole risks: alcohol is toxic to cats and can lead to tremors, rapid heartbeat, seizures, loss of consciousness and even death. Ethanol poisoning is possible even when cats drink small amounts of alcohol.

Caffeine

Cats are sensitive to the caffeine in things like coffee, tea and energy drinks. It can upset their stomachs, causing vomiting and diarrhoea. In large amounts, the stimulant can lead to caffeine toxicity, raising blood pressure and triggering an irregular heartbeat; it can also lead to loss of muscle control and seizures.

Chocolate

Chocolate contains a substance called methylxanthines, notes Dr Wismer. “Darker chocolate is more dangerous than milk chocolate,” she says. “White chocolate has the lowest level of methylxanthines while baking chocolate contains the highest.” Cats who eat chocolate can experience vomiting and diarrhoea, panting, excessive thirst and urination, hyperactivity, abnormal heart rhythm, tremors, seizures and even death. “Cats commonly sample chocolate, [but] they rarely ingest enough to cause more than mild stomach upset,” Dr. Wismer adds. “This may be due to cats not having sweet taste buds.”

Grapes and raisins

You know that grapes and raisins are doggie-don’ts, but these foods should be off-limits for cats, too. Like dogs, cats who eat grapes and raisins could develop kidney failure. In addition to avoiding the fruits, steer clear of all foods that could contain them, including grape juice, biscuits, protein bars, breads and other snacks that might have grapes and raisins as ingredients.

Milk

The children’s picture books were wrong: cats shouldn’t be given saucers of warm milk. In fact, cats lack lactase, the enzyme needed to process dairy foods; this feline lactose intolerance can lead to upset stomach, gas, cramping, and diarrhoea. Kittens who need to be bottle-fed should be offered specially formulated kitten formula – not cow’s milk, which lacks the nutrients they need to thrive.

Nuts

Walnuts, pecans, almonds and other nuts contain high amounts of oils and fats. While this satiating combination isn’t toxic to cats, Dr Wismer still suggests steering clear because the fats can cause vomiting and diarrhoea and, in severe cases, pancreatitis, a painful inflammatory condition. Cats should never be fed salted or chocolate-covered nuts. Macadamia nuts, which are highly toxic to dogs, cause no problems in cats, according to Dr Wismer.

Onions

The same ingredient that brings tears to your eyes can cause weakness, lethargy, loss of appetite, pale gums and dark orange-red urine in your cat. Onions – as well as other plants in the allium family, including shallots, spring onions, leeks and garlic – are linked to red blood cell damage and could lead to anaemia. Often, it takes a few days for the symptoms to appear.

“Cats may initially vomit, but within three to five days they will become lethargic, may have pale gums, and you may notice red urine,” says Dr. Wismer. “This happens due to the destruction of the red blood cells and loss of oxygen carrying capacity.” Exposure to small quantities (think onion powder or onion soup mix) could be especially problematic because of the high concentration of onions.

Raw eggs

Raw eggs can be a source of E. coli or Salmonella; both bacteria can cause illnesses ranging from fever and dehydration to vomiting. Cats do need protein, and cooked eggs are an excellent source of animal proteins – so grab the frying pan and make your cat some scrambled or fried eggs for breakfast.

Yeast

Store your pandemic-inspired sourdough starter in a safe place. Raw yeast, even in small amounts, is toxic. “When a cat ingests raw bread dough, the yeast continues to convert the sugars in the dough to carbon dioxide gas and alcohol,” Dr Wismer says. “This can result in bloated drunken pets, which could become a life-threatening emergency.” Although the raw yeast and dough are dangerous to cats, Dr Wismer says it’s ok to break bread with your cat on occasion, adding, “Cooked bread is safe for cats to enjoy.”

If your cat eats one of these toxic foods, call the vet or the Animal Poison Line immediately to determine next steps.

Jodi Helmer

Jodi Helmer is a North Carolina-based freelance writer who shares her home with an embarrassing number of rescue dogs and relies on four feral cats to patrol the barn. When she isn’t refilling food and water dishes, Jodi writes about animals for Scientific American, Sierra, WebMD, AKC Family Dog, Living the Country Life, and Out Here.