BAIT DEVELOPMENT FOR ORAL DELIVERY OF PHARMACEUTICALS TO RACCOONS (PROCYON LOTOR) AND STRIPED SKUNKS (MEPHITIS MEPHITIS).

Oral vaccination is one tool used to control wildlife diseases. A challenge to oral vaccination is identifying baits specific to target species. The US has been conducting oral vaccination against rabies since the 1990s. Improvements in bait development will hasten disease elimination. In Colorado, we examined a novel bait for oral vaccination and offered two different flavors, sweet and fish, to captive raccoons ( Procyon lotor ) and striped skunks ( Mephitis mephitis ) to assess consumption and flavor preference and observed bait removal by target and nontarget species in the field. During captive trials, raccoons and skunks consumed 98% and 87% of offered baits, respectively. Baits contained a sachet to simulate a vaccine package. Raccoons and skunks consumed 98% and 94% of the sachets, respectively. All unconsumed sachets were punctured, suggesting that animals had oral exposure to the contents. Raccoons preferred fish-flavored bait, but skunks did not have a preference. In the field, raccoons consumed the most baits, followed by fox squirrels ( Sciurus niger ). Other rabies host species (striped skunks, red foxes [ Vulpes vulpes ], coyotes [ Canis latrans ]) had very low visitation and were never observed consuming baits. High consumption rates by raccoons and skunks in captivity and observance of raccoons consuming baits in the field suggest that these baits may be useful for oral delivery of pharmaceuticals. Further field research is warranted to determine how to best optimize bait delivery.