Dr. Cathy Polley, (a local veterinarian) removed stomach contents per Detective Dale England’s request and sent the stomach samples to Washington State Crime Lab (WSCL) in Cheney, WA.  The State Crime Lab was unable to process the samples, so Dr. Polley requested the lab send the samples to Washington State University (WSU) or Washington Animal Disease Diagnostic Laboratory (WADDL).  Dr. Patricia Talcott MS, DVM, PhD., DABVT received the samples and tested the stomach contents submitted by the state lab.  Dr. Talcott also sent samples to California Animal Health & Food Safety Laboratory System for analysis and to Michigan State University Diagnostic Center for Population and Animal Health.  In each laboratory testing concluded no traces of anticoagulant rodenticides (Rat Poison) were detected.  The conclusion of each laboratory was Taxine, the toxic principle in Taxus spp., was detected in each sample.  The Yew plant is a common source of Taxine.  Yew plant was accessible to both horses and is suspected as the cause of death.

While stomach contents were being sampled, Detective England took and sent samples of the alleged Yew shrub growing in the northeast corner of the corral where the deceased Clydesdales were discovered.  The alleged Yew samples were sent to Paula Dinius, an Urban Horticulturist at WSU Extension Office in Wenatchee, WA.  Ms. Dinius was able to contact Dr. Ray Maleike who determined the Yew samples were in fact a Yew species, specifically a Taxus cuspidate (Japanese Yew) or possibly the Taxus X media (the inter-specific cross between T. cuspidate and English Yew T. baccata). 

The Yew shrub was in the close proximity of the deceased Clydesdales and the lab results proved the stomach contents contain Yew residue.  Consumption by domestic animals usually results in sudden death.

The investigation has been concluded with a finding of accidental death due to the toxic plants.

For comments or concerns, contact Lieutenant Jerry Moore 509-667-6840.