Cats explore the world with their mouths, and a curious cat who tastes something toxic can develop a life-threatening emergency in a matter of hours. Knowing which foods are dangerous — and understanding why — is one of the most important pieces of preventive knowledge a cat owner can have.
Onions, Garlic, and Chives
All members of the Allium family — onions, garlic, chives, leeks, shallots — are toxic to cats. These foods cause oxidative damage to red blood cells, leading to hemolytic anemia. Symptoms may not appear for several days after ingestion. While a small amount of garlic powder in food may not cause obvious signs, it is cumulative and should be avoided entirely. Cats are about five times more sensitive to Allium toxicity than dogs.
Xylitol
Xylitol is an artificial sweetener found in sugar-free gum, candy, some peanut butters, and a growing range of processed foods. In dogs it causes rapid insulin release leading to dangerous hypoglycemia (low blood sugar). In cats, the mechanism is less well understood but xylitol is still considered toxic. Even small amounts can cause liver failure and death. Keep all sugar-free products well out of reach of pets.
Chocolate
Chocolate contains theobromine and caffeine, both of which cats metabolize very slowly. Dark chocolate and baking chocolate are the most dangerous due to high theobromine concentration. Signs of chocolate toxicity include vomiting, diarrhea, rapid breathing, elevated heart rate, muscle tremors, and seizures. In severe cases, chocolate ingestion can be fatal.