How are drug-sniffing dogs trained to detect drugs? Are they mildly addicted?

Question

I am not sure if a dog can smell something without inhaling minute particles of the substance. In the case of hard drugs like heroin etc, would that mean that the dog has a mild dependency?

Please answer if you know. If it's just guessing, I can guess for myself. Thank you.

Answer 1

The key ingredient is a ball-crazy dog. You know the type; a dog that is
totaly nuts about chasing, catching, and otherwise frolicking with a tennis
ball. They find these dogs through a very scientific process whereby they
get a bunch of puppies together and throw tennis balls around until it becomes
apparent that one puppy is especially interested in ball-activities.

That puppy is rewarded with his very own ball, one scented with eau de cocaine
or eau de semtex, or whatever. They get these scents from a police-supply
outfit. They're just smells, no narcotic/explosive properties, so don't get
any ideas.

The puppy grows up with the scented ball. Whenever the dog is playing, it is
with the scented ball. If the dog seems pretty adept with scents, it might get
another ball with a different scent, but two seems to be the limit. Besides
just playing "catch," and other doggie-sports, the dog eventually learns the
game "find your ball!"

Thats the funny part. When the dog goes charging around the airport and starts
clawing at your suitcase, he's just looking for his stupid ball.

Answer 2

They are trained to react to certain smells. They are then given positive re-inforcement.
They dont inhale any of the drugs. The scent it and then sit/scratch whatever they have been trained to do.

Answer 3

They ar e not mildly addicted they are trained that if they smell the drugs they know becuase poluce and famous dog trainers train them.

Answer 4

Blondebarbis got it right, though at least one department I know of uses a tug toy and does not sent the actual toy but they play find your tug and always hide it under/with something sented so pretty soon the dog knows the tug is where the sent is.
so yeah they are sddicted and strongly - to their toy......