Toxic foods: the complete list
All allium family plants destroy red blood cells (haemolytic anaemia) in cats. Garlic is significantly more toxic per gram than onion. The effect is cumulative — repeated small exposures are dangerous. Powdered forms are more concentrated than raw. Applies to all preparations: raw, cooked, powdered, in sauces, in stock.
Can cause acute kidney failure. The toxic compound has not been identified, meaning there is no known safe dose. Applies to all products containing grapes or raisins: wine, juice, mince pies, fruit cake, trail mix.
An artificial sweetener found in sugar-free chewing gum, some peanut butters, dental products, and sugar-free baked goods. Causes severe hypoglycaemia and liver failure. Less studied in cats than dogs but considered highly dangerous. Check ingredient labels on any sugar-free product.
Cats have no tolerance for ethanol — even small amounts can cause vomiting, disorientation, breathing difficulty, and death. Applies to all alcoholic drinks and foods prepared with alcohol. Also be aware of fermented fruit or dough containing yeast, which produces ethanol internally.
Cats are highly sensitive to methylxanthines. Even a small amount of coffee or strong tea can cause rapid heart rate, tremors, and seizures. Energy drinks, caffeine tablets, and some headache medications all contain caffeine at dangerous concentrations for cats.
Contains theobromine and caffeine. Dark chocolate and baking chocolate are most dangerous; milk chocolate less so but still harmful. Cats rarely seek out chocolate but ingestion via unattended baked goods or treats happens. White chocolate contains negligible theobromine but is high in fat and sugar.
Raw salmon, trout, and some other fish contain thiaminase — an enzyme that degrades thiamine (vitamin B1). Thiamine deficiency causes neurological signs including seizures. Occasional small amounts are low-risk; feeding raw fish regularly is not. Cooked fish inactivates thiaminase.
Raw egg whites contain avidin, which blocks biotin (vitamin B7) absorption. Raw eggs also carry Salmonella risk. Cooked eggs are safe in small amounts.
Toxic mechanism in cats is not fully understood but macadamia nuts cause weakness, hyperthermia, and vomiting in dogs; the same risk is considered present in cats. Avoid all nut-based products.
Most adult cats are lactose-intolerant. Milk and cream commonly cause diarrhoea and gastrointestinal upset. Small amounts of hard cheese are low-risk but high in salt and fat. The "cats love milk" image is a myth that causes genuine digestive harm to many cats.
Crisps, salted nuts, processed meats, and instant noodles contain salt concentrations that can cause sodium ion poisoning: vomiting, diarrhoea, tremors, and in severe cases seizures. Cats' kidneys are not equipped to process high sodium loads.
If your cat eats something toxic
Call your vet or an animal poison line immediately — do not wait for symptoms. In the UK, the Animal Poison Line (01202 509000) provides specialist telephone advice. The ASPCA Animal Poison Control Center serves the US (fee-based).
Do not induce vomiting unless explicitly instructed by a vet — in cats, this risks aspiration pneumonia. Have the packaging or a clear description of the substance ready before you call.
For a broader list of household hazards — including toxic plants and cleaning products — see our cat-proofing checklist.