Development of a Self-Contained Carbon Dioxide Euthanasia Trailer for Large-Scale Euthanasia of Feral Swine

Range expansion of feral swine (Sus scrofa) continues to be pervasive in the United States. Lethal control of feral swine is an accepted management practice throughout the nation. Indirect lethal control measures (e.g., trapping) often require euthanasia and methods used must be humane, safe, and economical. Though cranial gunshot is a widely accepted method of euthanasia, in some cases it is not safe, legal for use, or practical. Alternate means for euthanasia of wildlife research subjects are needed at the Feral Swine Research Facility on the Kerr Wildlife Management Area (KWMA), Hunt, Texas, USA. The American Veterinary Medical Association approves a gradual fill method of carbon dioxide (CO2) euthanasia for some laboratory animals and livestock species, including domestic swine. We manufactured a self-contained CO2 euthanasia chamber on a 4.27-m (14-foot) dump trailer for the euthanasia of feral swine. We conducted 3 euthanasia trials of 5 feral swine during December 2014-February 2015 at the KWMA. Carbon dioxide administration began immediately postloading and commenced for 5 min at an average of approximately 18% chamber volume/minute. Recorded mortality rates were 100%. Results of this study and scalability of our system may have widespread impacts on wildlife euthanasia protocols for wildlife researchers and state game agencies across the nation. (C) 2016 The Wildlife Society.