Rhododendron — along with its close relative azalea — is a common and dangerous garden shrub.
All parts of the plant are toxic; leaves and flowers are the most commonly eaten.
Rhododendrons contain grayanotoxins that bind to sodium channels and prevent them from inactivating. This causes prolonged depolarization of nerve and muscle cells, producing GI signs, cardiovascular collapse and CNS depression. Honey made from rhododendron nectar ("mad honey") shares the same toxicity.
Sources
Ingestion of 0.2% of body weight in leaves can cause toxicity. For a 10 kg dog, that's about 20 g of leaves.
Contact your veterinarian or an emergency animal poison hotline immediately. Do not induce vomiting unless instructed by a vet.
callFind Emergency Vet