STP 2024 -- Compounded formulations of buprenorphine HCl extended-release polymer injection solution (BUP-ER) offer convenient, long-acting pain control for laboratory animals. Several long-acting buprenorphine formulations have recently been reported to cause significant injection site reactions in nonhuman primates and rodents. Similar injection site reactions to BUP-ER have been observed at our facility in G�ttingen Minipigs after telemetry device implantation, prompting a study in colony rabbits to investigate this occurrence in other species.