No prescription required. D.A.P. (Dog Appeasing Pheromone) collar for puppies and small dogs helps comfort them in situations they may find worrying or which make them apprehensive. The collar stays on the dog at all times helping with events both inside and outside the home including: - adjusting to a new environment (new home, strangers, shelters) - socialisation period - novel and unpredictable situations - fear related reactions expressed outside the home (traffic, other dogs, thunderstorms, gunshots, etc) May be combined with DAP diffuser Fits puppies and small dogs with necks up to 37.5 cm (15") Lasts for up to four weeks. A natural behavioural aid.