Leachate Analysis from an Organic Burial Pit Containing Euthanized Large Animals.

The disposal of animal mortalities creates surface and ground water pollution concerns. In the case of euthanized animals, there is particular concern for drugs residuals that may be mobilized in leachate as carcasses decompose. In this study, we describe an experimental organic burial pit containing mature dairy cattle euthanized after participation in a clinical vaccination trial. The animals were buried in wood chips to promote composting and rapid decomposition of the carcasses. The pit included a plastic liner that allowed rainfall derived leachate to be collected from the pit. New GC/MS detection methods were developed to analyze the leachate for the two barbiturates used to euthanize the animals, namely xylazine and pentobarbital. Our findings indicate that the xylazine degrades quickly, but that the pentobarbital was persistent over a period of several weeks and easily detectable in the leachate. We describe the burial experiment, the new GC/MS detection techniques for xylazine and pentobarbital, and leachate concentrations of xylazine, pentobarbital, E. coli, and oxygen demand.