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 now, or one of these services.

What do I do right now?
  • Australia
    Animal Poisons Helpline 1300 869 738 24 hours, every day · From $75
  • Austria
    Vergiftungsinformationszentrale 01 406 43 43 24 hours, every day
  • Belgium
    Centre Antipoisons 070 245 245 08:00 to 22:00 on weekdays, 10:00 to 22:00 at weekends · Human calls come first. The centre has no funding for animal work.
  • Canada
    Pet Poison Helpline (855) 764-7661 24 hours, every day · $89 for each incident
  • France
    Centre National d'Informations Toxicologiques Vétérinaires 04 78 87 10 40 08:30 to midnight, every day
  • Germany
    Giftinformationszentrum Bonn 0228 19240 24 hours, every day · Germany has no dedicated animal service. Human calls come first, so an animal call can wait.
  • Ireland

    Ireland has no animal poison service for owners. Call your veterinarian. An Irish veterinarian can consult the Veterinary Poisons Information Service in the United Kingdom.

  • Italy
    Centro Antiveleni di Milano 02 6610 1029 24 hours, every day
  • Netherlands
    Nationaal Vergiftigingen Informatie Centrum 088 755 8000 Veterinarians only 24 hours, every day · Call your veterinarian. Your veterinarian calls this line.
  • New Zealand
    Animal Poisons Helpline 0800 869 738 24 hours, every day
  • Sweden

    Giftinformationscentralen stopped answering questions about animals on 1 July 2018. Call your veterinarian or an animal hospital.

  • Switzerland
    Tox Info Suisse 145 24 hours, every day · From outside Switzerland, call +41 44 251 51 51.
  • United Kingdom
    Animal PoisonLine 01202 509 000 24 hours, every day · £35 from 08:00 to 20:00 Monday to Friday, £45 at other times
    Veterinary Poisons Information Service 020 7305 5055 Veterinarians only 24 hours, every day · A members only service. Your veterinarian calls this line.
  • United States
    ASPCA Animal Poison Control Center (888) 426-4435 24 hours, every day · A consultation fee applies
    Pet Poison Helpline (855) 764-7661 24 hours, every day · $89 for each incident

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

Countries with the most wild observations, from GBIF data.