Onion

Cats are more sensitive to onion: their smaller body weight and shorter red cell lifespan mean even small amounts can cause marked anaemia.

n-propyl disulfide and related organosulfur compounds

Drooling, vomiting, lethargy, pale gums, rapid breathing, weakness.

Seek veterinary care promptly with the amount and form ingested; do not induce vomiting at home.

Cats often become exposed by licking gravy, meat purees or table scraps; recipes containing onion are unsuitable for cats.

Onion contains organosulfur compounds such as n-propyl disulfide that oxidise red blood cells and form Heinz bodies, causing haemolytic anaemia; raw, cooked, dehydrated and powdered forms are all risky, and signs may appear days after eating.

n-propyl disulfide and related organosulfur compounds

Vomiting, diarrhoea, drooling, lethargy, reduced appetite, pale gums, rapid breathing, dark urine (haemoglobinuria), weakness.

Stop feeding and contact a veterinarian with the form (raw, cooked, powder) and approximate amount; pale gums or dark urine are emergencies.

Most exposures come from human food: burgers, stews, soups, baby food and seasoning mixes containing onion powder; Japanese breeds (Akita, Shiba Inu) are more sensitive.