Increased global movement of people and animals increases likelihood of foreign animal diseases (FAD), like African Swine Fever (ASF), being introduced into the US swine population. Due to the risk of pathogen amplification in infected animals, swine on affected premises would need to be depopulated as soon as possible. In general, the goal for rapid depopulation is 24-hours or less after a confirmed positive (new detection) or presumptive positive (subsequent detections) diagnosis has been made. The size of most US commercial swine operations makes achieving this 24-hour goal difficult, with large sow units being especially problematic due to number of large animals (>200 kg). Most current methods for swine depopulation and disposal are not good candidates for mass depopulation in sow units because they are either time consuming (delivered at the individual level), create an unacceptable risk of disease dissemination for other swine populations (e.g. pathogen dissemination during movement of carcass material to disposal sites), or are practically infeasible to facility designs. Water-based foam is a preferred method for poultry depopulation, but limited testing of water-based foam has been conducted on swine under field conditions and guidelines for their use under emergency situations are lacking. We sought to further investigate the effects of water-based foam depopulation to prepare the swine industry for mass depopulation and disposal events. The overall objective of this proposed mixed-methods project is to fill the critical gaps in scientific evidence to support an application for AVMA approval of water-based foam for depopulation of all ages of swine. Our findings demonstrate that depopulation with water-based foam reliably induced rapid unconsciousness (average of 2 minutes) and subsequent brain death in all age pigs. After 5 minutes in the foam, none of the pigs were recoverable, which means the process can be used to rapidly depopulate groups of swine from a modern swine facility. Additionally, 86.7% of industry stakeholders who observed depopulation of pigs with water-based foam indicated that water-based foam was a better depopulation method than any of currently approved methods (e.g. captive bolt, electrocution, CO2). Our findings support efforts to seek conditional AVMA approval of water-based foam as an emergency depopulation option for all ages of swine.

Contact Information: Andrew Bowman,