What are the symptoms of Oleander poisoning in cats?

drooling, vomiting, diarrhea, irregular heartbeat, weakness, collapse, death

Oleander

Q: Is Oleander toxic to cats?

Dangerous: EXTREMELY DANGEROUS — cardiac glycosides, potentially fatal. All parts of oleander (Nerium oleander) contain cardiac glycosides that affect the heart. Ingestion can cause fatal cardiac arrhythmias. Even a single leaf can be lethal. Oleander is an outdoor ornamental in warm climates and can be dangerous if cats have access to gardens or if cut branches are brought indoors. Source: ASPCA.

Dangerous

Verdict

EXTREMELY DANGEROUS — cardiac glycosides, potentially fatal.

Toxic principle: cardiac glycosides

Source: ASPCA · Verified 2026-06-12

If your cat ate this

Cats hide symptoms — don't wait and see. Even small amounts of certain substances can be fatal to a cat. Act fast.

1. Call your veterinarian immediately
US — National hotline: ASPCA Animal Poison Control Center (888) 426-4435 aspca.org(24/7, Consultation fee may apply.)
US — National hotline: Pet Poison Helpline (855) 764-7661 petpoisonhelpline.com(24/7, $89 per incident fee; also covers Canada.)
GB — National hotline: Animal PoisonLine 01202 509 000 animalpoisonline.co.uk(24/7, £35 per call (8am–8pm weekdays), £45 at other times.)
AU — National hotline: Animal Poisons Helpline 1300 869 738 animalpoisons.com.au(24/7)
NZ — National hotline: Animal Poisons Helpline 0800 869 738 poisons.co.nz(11am–7pm NZ time (currently being extended), Charges apply.)
CA — National hotline: Pet Poison Helpline (855) 764-7661 petpoisonhelpline.com(24/7, $89 per incident fee.)

Verified 2026-08-06

Verdict

All parts of oleander (Nerium oleander) contain cardiac glycosides that affect the heart. Ingestion can cause fatal cardiac arrhythmias. Even a single leaf can be lethal. Oleander is an outdoor ornamental in warm climates and can be dangerous if cats have access to gardens or if cut branches are brought indoors.