Human Foods That Are Toxic to Cats

by Curious Cat People February 17, 2023 6 min read

Human Foods That Are Toxic to Cats

Human Foods That Are Toxic to Cats

As cat parents, you know the temptation to just give in and allow your kitty some table scraps when she comes begging and pleading for your human food. A sliver of chicken breast from your dinner plate certainly won't harm her (though you'll be helping her develop some really bad habits!) but bear in mind that certain human foods can be poisonous to her. Here’s a look at some of the most toxic human foods that you should never feed your cat.

Human Foods That Are Toxic to Cats

Green tomatoes, tomato stems, and leaves

The truth is cats are not likely to eat raw, green tomatoes as the taste and texture do not appeal to them. However, they may nibble on the stem and leaves of a tomato plant, and these are very toxic for cats. If you are growing tomatoes at home and your cat is free to wander, do fence around the plant to discourage any nibbling by your cat. Tomatoes are members of the Solanaceae family of plants, also known as the nightshade, and they contain a bitter, poisonous alkaloid called Glycoalkaloid Solanine. This glycoalkaloid is found in large quantities at the stem and leaves of the tomato plant. The green tomato fruit does contain some glycoalkaloid but at a much lower concentration. As the tomato ripens, the level of glycoalkaloid drops significantly. A ripe red tomato has very minimal levels of glycoalkaloid, making the tomato fruit safe for consumption by humans and pets (dogs and cats). A little glycoalkaloid will not harm your cat but in large quantities, this substance can cause violent lower gastrointestinal symptoms, lethargy, and confusion.

Don't worry if you see tomatoes included in pre-made pet foods. They are made with ripe tomatoes and should cause no concern because they appear in relatively small amounts.  

Human Foods That Are Toxic to Cats

Grapes and Raisins

It’s a known fact that grapes and raisins are toxic to dogs. There are still many unknowns if these food items are toxic to cats but there is no reason to risk a dangerous situation, so it’s best to keep them away from your kitty. Our recommendation is not to give grapes or raisins to your cats. Instead of raisins, plain dried cranberries are safe for cats in moderation. Avoid sweetened or flavoured cranberries. To play it safe, try this cranberry treat made especially for cats - Fruitables Crunchy Salmon with Cranberry Cat Treats.


It's widely known that chocolate is dangerous for dogs. Chocolate is also toxic to cats. Theobromine found in chocolate can cause chocolate toxicity in both dogs and cats. This substance is found in the highest concentration in dark and unsweetened chocolate. Pure cocoa powder and plain, dark chocolate contain the highest concentrations of theobromine at 20 mg/g and 15 mg/g respectively, milk chocolate has much less at only 2 mg/g, and white chocolate has the least concentration of this substance at only 0.1 mg/g. The toxic dose of theobromine in cats is 200 mg/kg.  

Human Foods That Are Toxic to Cats


Unlike some highly toxic foods like chocolate, a small amount of avocado flesh will not harm your cat. However, it is always safer to err on the side of caution. Avocado leaves, seeds, tree bark, and the fruit itself contain persin, which can cause vomiting and diarrhea in cats. In large enough quantities, persin may even cause heart muscle damage. Though avocado is considered a heart-healthy human food that’s rich in good fats, it’s not heart-healthy for cats. If you’re looking to increase your kitty’s intake of good fats, consider adding this omega-3 supplement into her daily diet - Dom & Cleo Cod Liver Oil Supplements For Dogs & Cats.

Onions and garlic

Cats are more susceptible to onions and garlic poisoning than dogs. The amount of onions or garlic that it takes to poison your cat will vary depending on your cat’s weight, health, and breed. In most cases, a single clove of garlic is all it takes to poison a cat. An onion can become toxic to a cat if more than 1 gram (for every 2kg of body weight) is ingested. Both onions and garlic cause red blood cell damage and anemia in cats.

Cats can also be exposed to garlic and onion in the form of powder, which can be found in chips, soups, and seasonings. Do store away chips, seasoned snacks, instant food powders, and other cooking seasonings that may contain garlic or onion powder.  

Human Foods That Are Toxic to Cats

Rice. potato and other starchy foods

Though not toxic to cats, rice, potato, bread, noodles, and other starchy foods are not a part of a cat’s natural diet. Cats are obligatory carnivores and have no nutritional need for carbohydrates. It is OK to give a little as an occasional treat but too much carbohydrates can be “toxic” to a cat’s metabolism, leading to feline obesity or diabetes.

Lower-quality dry cat food can have excess amounts of carbohydrates - up to 50% carbohydrate content. Starchy foods like potatoes and rice are often used as a binder; to provide structure and texture to the dry kibble. They are also used as fillers and bulking agents, allowing the cat food manufacturer to use fewer meat products, and keeping the production cost lower. For some cats, a diet with excess carbohydrates may lead to other health complications like dental issues, obesity, and diabetes. If you’re worried about your cat’s carbohydrate intake, consider checking the cat food or treats’ nutritional value on the packages. A general rule, freeze-dried cat food like this Primal Freeze Dried Nuggets Chicken and Salmon Formula Cat Food will contain a lower amount of carbohydrates compared to traditional dry cat kibble.

Here’s a freeze-dried cat treats that’s made with 100% liver with no fillers or starchy bulking agent - Freeze Dry Australia Kangaroo Liver Freeze Dried Cat & Dog Treats.

Human Foods That Are Toxic to Cats


All types of alcohol are toxic to cats. While a small lick of an alcoholic beverage is not lethal, consuming a lot can be. Alcoholic beverages aren’t the only potential sources of alcohol poisoning in cats. Alcohol exposure can also occur from ingestion of hand sanitizer, mouthwash, fermenting fruits, and bread dough that contains yeast.


Most adult cats are lactose-intolerant. Like most mammals, cats become lactose intolerant as they mature, which means they have trouble digesting milk and other dairy products with high lactose content. Their digestive system cannot process dairy foods well, and the result can be digestive upset and diarrhoea. As such, if you would like to give milk to your kitty, choose a lactose-reduced or lactose-free milk like this Kit Cat 100% Natural Milk (Adult & Senior).

Coffee and caffeinated drinks

Caffeine in large enough quantities can be fatal for cats. Symptoms of caffeine poisoning include restlessness, rapid breathing, heart palpitations, and muscle tremors. Caffeine is not just found in tea and coffee, it can also be found in colas, energy drinks, some cold medicines, and painkillers. So, stash away these caffeinated foods and medication, and make sure they are not within reach of your cat!


Xylitol is a sweetener that is mostly found in human products like gum, candy, mouthwashes, human toothpaste, vitamins, and peanut butter. When your pet ingests xylitol, it is quickly absorbed into the bloodstream, resulting in a potent release of insulin from the animal’s pancreas. When the insulin increases rapidly it causes a rapid decrease in the blood sugar level, a condition called hypoglycaemia. This effect can occur within 10 – 60 minutes of ingestion and can lead to vomiting, lethargy, and even liver failure in pets. Xylitol is extremely toxic to our pets and is best avoided.  

Human Foods That Are Toxic to Cats

Common signs of food poisoning in cats

There are many different reactions to poisoning. Signs that might show that your cat has been poisoned include:

  • Excessive salivation
  • Vomiting
  • Diarrhoea
  • Wheezing or breathing difficulties
  • Excessive thirst
  • Changes in drinking, urinating, and appetite
  • Shock or collapse
  • Seizure
  • Blood in stool, vomit, saliva, or urine
  • Lethargy or weakness

Symptoms may vary depending on the type of food poisoning. So, it's important to monitor your cat and contact your vet if symptoms persist or worsen. 

What to do if your cat ate a potentially toxic food item

No matter how cautious you are, there’s always a possibility that your kitty can find and swallow what she shouldn't. It's a smart idea to always keep the numbers of your local vet and the closest emergency clinic where you can find them easily and swiftly in an emergency. If you think your cat has consumed something toxic, call for emergency help at once.  








Katherine Khoo
Katherine is a Pet Nutrition Specialist and GDP’s Pet Wellness Advisor. She is committed to helping pet owners make informed dietary and lifestyle choices in nurturing healthy pets. Katherine is also a practicing Nutritional Therapist (human nutrition) and has been helping hundreds of clients to heal naturally with nutrients.

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