Is Oleander Toxic to Cats and Dogs?
Oleander is severely toxic to cats and dogs — all parts (even dried leaves and vase water) contain cardiac glycosides that cause dangerous heart problems. Call a vet at once.
Potentially life-threatening — treat any exposure as an emergency.
Potentially life-threatening — treat any exposure as an emergency.
In an emergency, do not wait.
Medical disclaimer: This tool is for general information only and isnot a substitute for veterinary diagnosis or treatment. Toxicity depends on the amount, your pet’s size, and health history. If your pet may have ingested something harmful, contact your veterinarian or a poison control hotline ((888) 426-4435 / (855) 764-7661) immediately — do not wait for symptoms to appear.
What is Oleander?
Oleander is severely toxic to cats and dogs — all parts (even dried leaves and vase water) contain cardiac glycosides that cause dangerous heart problems. Call a vet at once.
Also known as: nerium oleander, rose bay, rose laurel.
Symptoms to Watch For
🐕 In Dogs
- Vomiting, diarrhea, and drooling
- A slow or irregular heart rate and abnormal heart rhythm
- Weakness, tremors, and collapse
- In serious cases: death from heart failure
🐈 In Cats
- Vomiting, drooling, and diarrhea
- Abnormal heart rhythm and a slow heart rate
- Weakness, tremors, and collapse
- Death from heart failure in serious cases
What to Do If Ingested
- Call a veterinarian or poison hotline immediately.
- Remove any remaining plant material from the mouth.
- Note how much was eaten — all parts are toxic, even dried leaves and water from a vase.
- Do not induce vomiting unless a veterinarian instructs you to.
Steps apply to both cats and dogs. When in doubt, call a vet or poison hotline before acting.
When to Call the Vet Immediately
Call your veterinarian or a poison control hotline right away if you notice any of these:
- Any part of an oleander was eaten
- Vomiting, weakness, or collapse
- A slow, fast, or irregular heartbeat
- Tremors or seizures
Frequently Asked Questions
Frequently Asked Questions
Is it true that all parts of the oleander are toxic?
Yes. Every part of the oleander plant — leaves, flowers, stems, seeds, and roots — is highly toxic, and the toxins remain active even when the plant is dried. Even water from a vase containing oleander can be poisonous. Never burn oleander and let pets near the smoke or ashes.
What do oleander toxins do to the heart?
Oleander contains cardiac glycosides, which act like a powerful heart medication in overdose. They cause a dangerously slow or irregular heartbeat, abnormal rhythms, low blood pressure, and can lead to fatal heart failure. This is why any ingestion is an emergency.
How much oleander is lethal?
A very small amount can be dangerous — even a few leaves have caused death in large animals, and pets are smaller. Because the cardiac glycosides are so potent, treat any ingestion as a life-threatening emergency and call a vet immediately.
Sources
This entry is reviewed against the following authoritative veterinary sources.
- ASPCA Toxic and Non-Toxic Plants Database
- Merck Veterinary Manual — Toxicology
- Pet Poison Helpline — Poisons
Last reviewed: 2026-07-11