✕ Toxic

Scallions / Green onions

Scallions and green onions (Allium fistulosum and Allium cepa) are members of the Allium family and are severely toxic to cats — sharing the same mechanism as garlic, onions, chives, and leeks. They contain organosulfur compounds that oxidise feline haemoglobin, forming Heinz bodies and triggering haemolytic anaemia. All parts and all preparation forms are dangerous.

Important Notes

Toxic compounds: N-propyl disulfide and organosulfur compounds (alk(en)yl cysteine sulfoxides); all parts toxic including white bulb, green tops, and cooked forms

Mechanism: oxidative damage to haemoglobin creates Heinz bodies; the spleen destroys affected red blood cells, causing haemolytic anaemia

Symptoms: lethargy, weakness, pale or yellowish gums, rapid breathing, loss of appetite, reddish-brown urine; onset often delayed 3–5 days

Scallions are commonly used in Asian cooking — stir-fries, soups, dumplings — keep cats away from these foods

Contact your vet immediately if ingestion is suspected

Potentially Toxic Parts

Powder

Juice

Possible Symptoms Reported in Cats

Tachypnea and Dyspnea (Breathing Difficulties)

Respiratory · After a lag of several days.

Lethargy, Weakness, and Depression

Neurological · After a lag of several days (typically 2 to 4 days).

Pale Mucous Membranes and Jaundice (Icterus)

Gastrointestinal · After a lag of several days.

Tachycardia (Rapid Heart Rate)

Cardiac · After a lag of several days.

Hemoglobinuria (Dark Urine)

Gastrointestinal · After a lag of several days.

Cold Sensitivity

Neurological · Several days after ingestion.

Because scallions (green onions) are members of the Allium genus

Metabolic

Vomiting, Diarrhea, Abdominal Pain, and Drooling

Gastrointestinal · Within 1 day of ingestion.

Allium Breath Odor

Gastrointestinal · Shortly after ingestion.

Disclaimer: This summary was compiled from multiple sources and is for informational use only. It is not a diagnosis or treatment plan. Toxicity can vary based on the substance, amount, plant part, and individual cat. If you think your cat may have been exposed to a toxic substance, contact a veterinarian right away.