Rhododendron spp.

Rhododendron spp. is toxic to cats, dogs and horses. The reported severity is critical. Also known as Rhododendrons and Azaleas, Bog Labrador Tea and Great Rhododendron.

dogs cats horses

Mild Moderate Severe Critical

This plant is known to be potentially deadly!

  • If you're comfortable with the risk, ensure this plant is out of reach of your animal.
  • If you suspect your animal has ingested portions of this plant, immediately consult your veterinarian.
  • If your animal is experiencing any of the associated symptoms, immediately contact your veterinarian's emergency number for further instructions.

If your animal ate this plant, call your veterinarian, the ASPCA Animal Poison Control on (888) 426-4435 or the Pet Poison Helpline on (855) 764-7661. Fees may apply.

Symptoms to watch for

Vomiting Diarrhea Drooling Weakness Coma Low Blood Pressure Depression Cardiovascular Collapse Death Loss Of Appetite Colic Incoordination Stupor Paralysis Cardiac Arrhythmias Cardiac Failure CNS Depression Abdominal Pain Weak Pulse Recumbency Slow Heart Rate

The color of each symptom follows the severity scale above.

About

Rhododendron, from Ancient Greek ῥόδον (rhódon), meaning "rose", and δένδρον (déndron), meaning "tree", is a very large genus of about 1,024 species of woody plants in the heath family (Ericaceae). They can be either evergreen or deciduous. Most species are native to eastern Asia and the Himalayan region, but smaller numbers occur elsewhere in Asia, and in North America, Europe and Australia.

How this plant poisons

Some species of rhododendron are poisonous to grazing animals because of a toxin called grayanotoxin in their pollen and nectar. People have been known to become ill from eating mad honey made by bees feeding on rhododendron and azalea flowers. Xenophon described the odd behaviour of Greek soldiers after having consumed honey in a village surrounded by Rhododendron ponticum during the march of the Ten Thousand in 401 BCE. Pompey's soldiers reportedly suffered lethal casualties following the consumption of mad honey that was deliberately left behind by Pontic forces in 67 BCE during the Third Mithridatic War. Later, it was recognized that honey resulting from these plants has a slightly hallucinogenic and laxative effect. The suspect rhododendrons are Rhododendron ponticum and Rhododendron luteum (formerly Azalea pontica), both found in northern Asia Minor. Eleven similar cases during the 1980s have been documented in Istanbul, Turkey. Rhododendron is extremely toxic to horses, with some animals dying within a few hours of ingesting the plant, although most horses tend to avoid it if they have access to good forage. Rhododendron, including its stems, leaves and flowers, contains toxins that, if ingested by a cat's stomach, can cause seizures and even coma and death.

Common Names

  • Rhododendrons and Azaleas
  • Bog Labrador Tea
  • Great Rhododendron
  • Tsutsusi Azalea
  • Common Rhododendron
  • Marsh Labrador Tea
  • Pinxter Flower
  • Flame Azalea
  • Mock Azalea
  • Pacific Rhododendron
  • Western Azalea
  • Rhodora
  • Red Azalea
  • Catawba Rhododendron
  • Mountain Azalea
  • Rusty-Leaved Alpenrose
  • Swamp Azalea
  • White-Flowered Rhododendron
  • Western Labrador Tea
  • Early Azalea
  • Lapland Azalea
  • Lovely Azalea
  • Hybrid Rhododendron
  • Hairy Alpenrose
  • False-Gold-Flower Rhododendron
  • Daurian Rhododendron
  • Korean Rhododendron
  • Yellow Azalea
  • Taiwan Azalea

Also recorded as Azaleas, Rhododendron, Rhododendrons, Rhododenron, Rosebay and azalea.

Facts

Family
Ericaceae
Duration
Perennial
Growth habit
Shrub, Tree
In the wild
US, GB, CN, SE, FR, JP + more
Source
Wikipedia, CC BY-SA 4.0
Elsewhere

Countries with the most wild observations, from GBIF data.