Drugs dogs are two kinds, active and passive.
They are always hound or retriever breeds (beagle, springer/cocker spaniel, labrador retriever), although sometimes mongrels from dogs’ homes are used if they have the right intelligence and termperament.
Other normal police dogs are guard breeds (GSD/Rottweiller) They are known as GP (General Purpose) dogs or Tactical dogs – these are used by the Firearms unit and are taught to be less frightened of gunfire and not to grab at sticks, so they won’t accidentally grab at an armed officer’s carbine!)
When deployed by the Police both drugs dogs and GP dogs are often kept in the same dog unit van; which is why their roles are often confused (although there may be some GSD’s which are used as sniffer dogs)
They are usually trained to recognise all kinds of recreational substances.
Active dogs are the ones which signal to their handler immediately when they have found something.
Passive dogs are sent into an area to locate and memorise key spots where drugs may have been used or distributed. They then at a later time (for instance after the venue has been closed) go back into the area and indicate to their handler where the drugs were (a bit like Lassie)
Most dogs used at festivals are active dogs, provided by private companies rather than the Police (there would not be enough dogs to sweep the area otherwise). I would expect they are suffering sensory overload in many cases; but usually they are deployed in such a way that “likely” people are “directed” (by a combination of various hairy-arsed security and cops) towards the dogs in an area with less distractions).
Legal festivals these days are full of CID and uniformed cops anyway;paid for by your ticket costs.
Incidentally black Labrador Retrievers which sometimes appear at stations are trained to sniff out explosives rather than drugs and come from the MOD rather than the Police – but are often deployed along with British Transport police3 drugs dogs.
