Is Yellow Oleander toxic to cats?

Yes — yellow oleander is toxic to cats according to the ASPCA. Keep it well away from any cat that chews plants; reactions can be significant. All parts — leaves, flowers, seeds, roots, and milky sap — contain cardiac glycosides (thevetin A and B, peruvoside, neriifolin) that inhibit sodium-potassium ATPase in cardiac muscle. Toxic to dogs, cats, horses, and humans; ingestion of even one seed can cause life-threatening arrhythmia, vomiting, and cardiac arrest. Note: Thevetia peruviana is a synonym of Cascabela thevetia; the accepted name in current taxonomy is Cascabela thevetia. Seek emergency medical attention immediately if any part is ingested.

All parts — leaves, flowers, seeds, roots, and milky sap — contain cardiac glycosides (thevetin A and B, peruvoside, neriifolin) that inhibit sodium-potassium ATPase in cardiac muscle. Toxic to dogs, cats, horses, and humans; ingestion of even one seed can cause life-threatening arrhythmia, vomiting, and cardiac arrest. Note: Thevetia peruviana is a synonym of Cascabela thevetia; the accepted name in current taxonomy is Cascabela thevetia. Seek emergency medical attention immediately if any part is ingested. Signs usually appear soon after chewing rather than hours later — watch for drooling, pawing at the mouth, vomiting, loss of appetite, or unusual lethargy after your cat has had access to yellow oleander.

Stay calm. Remove any plant from your cat's mouth and take the plant away. Note how much was eaten and when, and do not induce vomiting unless told to. Call your vet or the ASPCA Animal Poison Control Center on (888) 426-4435 and follow their advice; a leaf or photo helps the vet treat it correctly.

The ASPCA classification Growli uses applies to both cats and dogs: Yellow Oleander is toxic to dogs as well. See the full yellow oleander pet-safety guide for both species.

For a similar look without the risk, see the best cats-safe plants list — every plant there is ASPCA non-toxic to cats and dogs.