The drug detection dog discipline is split into two main fields, Passive and Pro-active. The pro-active dog does not confront the public and is therefore permitted a natural indication. The main users in the UK are government agencies but the market is rapidly expanding in the civil sector especially as a source of supply for trained dogs.

Drug detection dogs have a high commercial value being employed in the front line in the war against drugs.

The Passive response drug detection dog is trained to detect drugs hidden on the person. Working in public areas, principally in air and sea ports, the dogs monitor people passing by and indicate by sitting in front of the suspect.

The taller gun dog breeds are used because the dog requires sufficient height to be able to scent drugs on the upper body. Springer spaniels are generally excluded from this discipline. Spaniels however, are recommended as first choice pro-active dogs.