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Is Yellow Oleander Toxic to Dogs?

☠️ 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 and potentially fatally toxic to dogs. Its thevetin cardiac glycosides disrupt heart rhythm, and one seed can be enough.

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

What makes it toxic

Cardiac glycosides (thevetin A and B, neriifolin) throughout the plant, concentrated in the seed kernels. They inhibit the sodium-potassium pump in heart cells, producing arrhythmias and heart block.

Warning signs to watch for

Drooling, vomiting and diarrhea within hours, then weakness, stumbling, slow irregular pulse, cold extremities, dilated pupils, tremors and collapse.

What to do if your dog eats it

Go to the emergency vet immediately with any plant or seed material. Treatment needs ECG monitoring, anti-arrhythmic drugs and fluid therapy started early — this plant kills treated-late patients.

Common questions

Is one yellow oleander seed really lethal to a dog?

It can be, especially for small dogs — the kernel is among the most concentrated plant cardiac toxins. Human deaths from a few seeds are documented worldwide.

Can a dog be poisoned by chewing fallen yellow flowers?

Yes — glycosides are present in flowers and leaves too, at lower doses than seeds but still capable of real arrhythmias.

More plants checked for dogs

Pothos☠️ ToxicYes, pothos is toxic to dogs. Chewing any part of the vine releases calcium oxalate crystals thaAloe Vera⚠️ Mildly ToxicAloe vera is mildly to moderately toxic to dogs. The skin and latex layer of the leaf contain coSpider Plant✅ Non-ToxicNo, spider plants are non-toxic to dogs. A dog that nibbles the arching leaves is not at risk ofEaster Lily⚠️ Mildly ToxicEaster lilies are only mildly toxic to dogs — they usually cause stomach upset, not the fatal kiSago Palm☠️ ToxicYes — sago palm is severely toxic to dogs, with a documented fatality rate around 50% when untreBoston Fern✅ Non-ToxicNo, Boston ferns are non-toxic to dogs. Chewing a frond will not poison your dog.

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.