Kaput\u3csup\u3e®\u3c/sup\u3e Feral Hog Bait Containing 0.005% Warfarin: An Overview of its Usefulness against Feral Hogs and Safety to Wildlife and Humans

Warfarin has been approved for use in the United States as a rodenticide since 1948. The United States Environmental Protection approved Kaput® Feral Hog Bait (0.005% warfarin) for use as a toxicant to control wild pigs in 2017. The level of warfarin is 80% less than in commercial rodenticide formulations. Since 1994 we have conducted wildlife safety studies examining the potential effects of warfarin on non-target mammals and birds. Over a 25-year period, non-target toxicity research was completed with European ferrets, pied magpies, mallard ducks, bobwhite quail, Norway rats, house mice, and American alligator to assess primary and secondary exposure to warfarin baits. Pen studies were conducted on birds to examine primary exposure to birds feeding on baits ranging in concentration of 0.05% to 0.025% warfarin. Laboratory studies were completed where warfarin baits were fed to rats or prairie dogs and the carcasses presented to ferrets and magpies to simulate wildlife scavenging on carcasses. A low-dose warfarin was presented to Norway rats to simulate spilled Kaput Feral Hog Bait exposure. A low-dose warfarin hog bait reduces wildlife toxicity potential significantly while at the same time is efficacious against wild pigs. Field studies in Texas over three years (2015-2017) showed consistent efficacy of \u3e95% for feral hogs. Daily systematic searches during baiting and post-baiting periods on treatment and control plots showed no non-target effects. In this paper we review studies conducted with warfarin over the past 25 years and the results of our findings