Toxicity to pets

Rhododendrons contain grayanotoxins within all parts of the plant. Ingestion of rhododendron by animals results in gastrointestinal distress (e.g., vomiting, hypersalivation, drooling, colic), cardiovascular abnormalities (e.g., heart rhythm irregularity, low blood pressure), and neurological signs (e.g., depression, seizure). Severe clinical signs are expected with large ingestion (e.g., grazing by goats or cattle) but also may occur in cats or dogs that consume only a few leaves or flowers.