Veratrum californicam. American false hellebore (V. viride) is the most common and is found in most northern States from East to West including Canada. Others species include V. alblum
A plant of altitudes above 8000 feet preferring moist mountain valleys and meadows
Sheep most commonly, but llamas and alpacas and possibly cattle are affected.
Over 50 complex alkaloids, many with potent hypotensive effects have been isolated from Veratrum species. Highest concentration of the alkaloids are found in the young plant in early spring. The roots and all parts of the plant are toxic. Experimentally it has been shown that 1.25mg/kg body weight of the root is lethal to sheep, while a dose of 0.88mg/kg body weight of ground root produce craniofacial malformations in the lambs without causing severe toxicity in the ewe.
Erect, 1-2 meters tall, with short perennial root stalks. The leaves are smooth, alternate, parallel-veined, broadly oval to lanceolate, 12-30 cm long, 12 cm wide, in three ranks and sheathed at the base. The inflorescence is a panicle of very numerous, small, greenish-white flowers, the lower ones often staminate and the upper ones perfect. The fruit is 3-chambered with several seeds.
Veratrum californicum has whitish flowers on an erect panicle. It is found at higher altitudes of the rocky Mountains.
Veratrum viride is very similar, but has greenish-white flowers produced in a pannicle with drooping lower branches. It grows at lower altitudes throughout North America.
Some alkaloids (cyclopamine) have specific teratogenic effects in sheep. Pregnant ewes consuming Veratrum in the 13-14 day of pregnancy produce lambs with a single eye and deformed facial bones.
Veratrum causes cyclops in lambs born to ewes eating the plant on the 13-14th days of gestation. If eaten on the 27-33rd. days of gestation, lambs are born with tracheal agenisis. Lambs with cyclopia have a single eye and varying degrees of malformation of the bones of the mandible and maxilla. Lambs are either born dead or die shortly after birth. Consumption of the Veratrum from the 28-30th. days of gestation may result in lambs with shortended legs.
Decreased blood pressure leading to hypotension and shock. Decreased heart rate often occurs.
Lambs born with cyclops are highly suggestive of veratrum poisoning. Similarly lambs born with shortened legs , or which die due to the fact they have a collapsed or absent trachea should lead to suspicion of veratrum poisoning.
Preventing pregnant ewes in their first trimester from having access to Veratrum eliminates the teratogenic effects of the plants.
1. Welch KD et al. Dose-response evaluation of Veratrum californicum in sheep. In In Poiusoning by plants, Mycotoxins and Related Toxins. Riet-Corre F, Pfister J, Schild AL, Wierenga T (Eds) CABI 2009, 243-250.
2. Binns W, James LF, Shupe JL, Everett G. A congenitalcyclopian type malformation in lambs induced by the maternal ingestion of a range plant, Veratrum californicum. Am J Vet Res 1963. 24:1164-1175.