Antelope deaths traced to poisonous yew bushes
Landscape plant deadly to horses, livestock, humans and pets
by Wyoming Game & Fish
November 24, 2009
CHEYENNE - The deaths of 10 pronghorn antelope in the Cheyenne area over the past month has been traced to consumption of foliage of poisonous yew bushes.
In mid October, Game and Fish received reports of dead and dying antelope in the Winchester Hills area south of Cheyenne. At that time, game warden Todd Kittel collected six of the seven animals found at Winchester Hills and took them to the Wyoming Game and Fish Department laboratory in Laramie for analysis. Nearly a month later, Kittel investigated reports of three dead antelope in the Round Top Road area north of Cheyenne. In both instances, the deaths of the antelope coincided with heavy snowfall in the region. It is likely the added snow cover drove the antelope close to residences in search of food. All animals were found within 200 yards of the yew bushes.
WGFD assistant wildlife veterinarian Cynthia Tate necropsied the pronghorns and subsequent toxicology analysis revealed that it was indeed the consumption of yew foliage that had killed the animals. The poisonous properties of yew plants is well documented. There have been numerous instances of livestock dying after eating leaves of yew trees and bushes. The entire plant except for the fleshy berry contains cardiotoxins. This includes the bark, foliage and seeds. Since the seeds are contained within the berry, the berries of the plant should be considered off limits as well. It only takes 6-10 ounces of the foliage to kill a horse or a cow. If ingested, it is also toxic to humans and pets. In ancient times, potions made from yew foliage was used as a means of carrying out death sentences in some cultures.
In winter, the toxin accumulates in greater concentrations in the foliage and the plant is even more potent. Kittel said homeowners, especially in rural areas frequented by wildlife, may wish to consider the potential effects on wildlife when choosing shrubbery for landscaping.