The invention includes compositions for transmucosal administration to an animal comprising at least one active agent and a pharmaceutically acceptable carrier. A preferred active agent is selected from the group consisting of meloxicam, carprofen, enrofloxacin, clemastine, diphenhydramine, digoxin, levothyroxine, cyclosporine, ondansetron, lysine, zolpidem, propofol, nitenpyram, ivermectin, milbemycin, and pharmaceutically acceptable salts, solvates and esters thereof. In another embodiment, the invention includes methods of treating or preventing a condition in an animal comprising transmucosally administering a composition comprising a therapeutically or prophylactically effective amount of an active agent and a pharmaceutically acceptable carrier.