- Alcohol can cause severe liver and brain damage. As little as a tablespoon can lead to problems for your cat.
- Chocolate contains theobromine. It is in all forms of chocolate, and most concentrated in dark chocolate and unsweetened cooking chocolate. Chocolate ingestion can cause heart problems, muscle tremors, or seizures. Chocolate also contains caffeine.
- Coffee, Tea, Energy Drinks. These contain caffeine that can cause your cat to become restless, have rapid breathing, heart palpitations and muscle tremors.
- Dairy Products. Some cats are lactose intolerant and if they eat dairy products it can cause vomiting and diarrhea.
- Grapes and Raisins. Cats are less likely to eat these so cases are rare however, dogs can suffer acute kidney failure from eating grapes or raisins, so it is best to not to risk your cat’s health and not let him eat these foods.
- Onions and Garlic. All members of the onion family can cause problems if eaten in sufficient quantity. A little bit of onion or garlic in some sauce is not likely to cause any problems. However, eating a clove of garlic or a green onion may cause digestive upset. Eating some type of onion on a regular basis could cause anemia.
- Xylitol. This is a sweetener used in a lot of sugar-free foods, especially chewing gum. There are no records of cats becoming ill from this product, but in dogs it can cause a severe drop in blood sugar (which can cause seizures/convulsions or even death) followed by liver failure. Therefore it is better to be safe and not let your cat eat foods that contain this ingredient.