Sneezeweed grows at altitudes of 5,000-10,000 feet in moist but well drained soils of mountain meadows and aspen groves.
Sheep especially, but cattle and horses are susceptible to poisoning. Goats seem tolerate much more of the plant before being affected.
Orange sneezeweed (Dugaldia hoopesii)
Dugaldin (hymenovin), a sesquiterpene lactone, is highly irritating to the mucous membranes of the respiratory and digestive tracts causing sneezing and projectile vomiting. The toxic dose is 0.3-1.0% body weight of the green plant. If eaten in large quautity death may result in a 1-2 days. More commonly, small amounts of the plant are eaten over time which leads to the more typical digestive signs seen
Perennials growing to 2 1/2 feet in height, with numerous broad clasping leaves near the base of the stem. Multiple flowers are large and showy with 3-5 toothed orange/yellow petals up to 2 inches in length.
Decreased appetite, bloating, teeth grinding and rumen stasis may be seen initially. Projectible vomiting of rumen contents leading to dehydration, weight loss, weakness and inhalation pneumonia. A common name for the disease is 'Spewing sickness'
Muscle weakness, ataxia, especially in lambs causing them to lag behind the flock.
Remove animals from the source of the sneezeweed and provide nutritious food and water.
Sheep with projectile vomiting grazing orange sneezeweed.
Overgrazing mountain rangeland leads to orange sneeze weed proliferation.
1. Ivie GW et al. Isolation of Hymenovin from Hymenoxys richardsonii (Pingue) and Dugaldia hoopesii (Orange Sneezeweed). J Aric Food Chem 24:680-682, 1976.