Toxic Principle

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.

Description

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.

Gastrointestinal

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.

Congenital Defects

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 agenesis. 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 Veratrum from the 28-30th days of gestation may result in lambs with shortened legs.

Cardiovascular system

Decreased blood pressure leading to hypotension and shock. Decreased heart rate often occurs.

Diagnosis

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.

Special Notes

Preventing pregnant ewes in their first trimester from having access to Veratrum eliminates the teratogenic effects of the plants. References: 1. Welch KD et al. Dose-response evaluation of Veratrum californicum in sheep. In Poisoning 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.