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Is Yellow Oleander Toxic to Cats?

☠️ ToxicSeverity: Severe
✅ Cross-checked against veterinary poison-control guidance · Oct 2026 audit
⚠️ Educational info only. If your pet just chewed something and looks unwell, skip the reading and call your vet or Pet Poison Helpline (US): (855) 764-7661.
Yes — yellow oleander is severely toxic to cats. Every part carries cardiac glycosides that can stop the heart, with the seeds the most concentrated.

Also known as: Lucky Nut, Be-Still Tree, Mexican Oleander, Thevetia peruviana · Thevetia peruviana

What makes it toxic

Thevetin, thevetin B and related cardiac glycosides in all tissues, densest in the kernels of the yellow nuts. Like oleander, they force dangerous heart rhythms and disturb electrolytes.

Warning signs to watch for

Vomiting, drooling and diarrhea first, then profound weakness, slow or irregular heartbeat, dilated pupils, trembling and collapse within hours.

What to do if your cat eats it

Absolute emergency. Go to a veterinary ER immediately with plant or seed material. Heart-rhythm drugs, electrolyte correction and monitoring save lives here — waiting costs them.

Common questions

Are yellow oleander seeds more dangerous than the leaves?

Yes — a single kernel holds enough glycoside to be lethal to small animals, but leaves and flowers also poison. Nothing about the plant is safe.

How is yellow oleander different from common oleander?

Different genus (Thevetia vs Nerium) but the same deadly cardiac-glycoside mechanism. Treat both as top-tier pet hazards.

More plants checked for cats

Pothos☠️ ToxicYes, pothos is toxic to cats. Chewing the leaves or vines releases sharp calcium oxalate crystalAloe Vera⚠️ Mildly ToxicAloe vera is mildly to moderately toxic to cats. The gel is famously soothing for human skin, buSpider Plant✅ Non-ToxicNo, spider plants are non-toxic to cats. They are one of the best houseplants for homes with curEaster Lily☠️ ToxicYes — and this is one of the most dangerous plants a cat can meet. Every part of an Easter lily,Sago Palm☠️ ToxicYes — sago palm is severely toxic to cats and among the deadliest houseplants. Every part contaiBoston Fern✅ Non-ToxicNo, Boston ferns are non-toxic to cats — a classic choice for plant-loving cat households.

This page is general educational information, not a substitute for professional veterinary advice. Every pet is different — if your animal ate something concerning, contact your veterinarian or a pet poison hotline right away. Checking what your pet can eat? Visit our sister site SafeOrToxic.