Onions, garlic, chives, and leeks
These can be raw, cooked, dried, or powdered. They damage red blood cells and can cause anemia.

Chocolate and caffeine
This includes chocolate, coffee, tea, and energy drinks. These affect the heart and nervous system and are toxic to cats.

Grapes and raisins
Even small amounts can cause kidney failure.

Alcohol
Very small amounts are extremely dangerous for cats.

Xylitol
An artificial sweetener found in sugar free gum, candy, baked goods, and some peanut butters. It can cause serious liver problems.

Milk and dairy products
Most adult cats are lactose intolerant, which can cause diarrhea and stomach pain.

Raw fish and raw meat
These can contain harmful bacteria or parasites. Raw fish can also cause a vitamin B1 deficiency.

Bones
Cooked or raw bones can splinter, cause choking, or injure the mouth and digestive tract.

Salty or heavily seasoned foods
Foods like chips, fast food, soups, and sauces can cause salt poisoning or dehydration.

Raw dough
Yeast dough can expand in the stomach and produce alcohol.

Dog food
Dog food does not contain essential nutrients cats need, such as taurine, and can cause health problems over time.

Large amounts of tuna meant for humans
Occasional small amounts may be okay, but feeding it regularly can lead to malnutrition or mercury exposure.