Toxic Parts:
all, especially the leaves
terpenes, grayanotoxins
Flower Color:
  • flower color
  • flower color
  • flower color
  • flower color
woodlands, gardens, ornamental

Time of Greatest Risk


Geographical Distribution

Azalea distribution - United States

Related Species


Rhododendron spp

Rosebay, Rhododendron, Rhodora, Rosa Laurel
6/ 10
Azaleas (Rhododendron spp.) are evergreen or deciduous flowering shrubs which are a commonly planted ornamental worldwide.
There are over 800 species of Rhododendron spp., all with flowers of various colors and are bell-shaped or funnel-shaped. The showy flowers display large, spectacular blooms ranging in colors of red, pink, white, and yellow.

Toxic components
Azaleas and other relatives of rhododendron species contain grayanotoxins (andromedotoxin), and sodium channel activators. Ingestion of 1-2 lb of green leaves can be toxic to horses and known to cause acute colitis in adult horses. Most cases of poisoning occur in the winter, when there is little available forage to eat or in the summer when there have been frequent droughts, and little pasture available to eat.


  • Increased Salivation
  • Diarrhea
  • Colic
  • Muscular Weakness
  • Bradycardia
  • Cardiac Abnormalities
  • Tremors
  • Death