Originally Posted by
pewpew
Wirelessly posted (Mozilla/5.0 (BB10; Touch) AppleWebKit/537.35+ (KHTML, like Gecko) Version/10.2.1.3442 Mobile Safari/537.35+)
They're trained to alert when the handler wants them to

Call us both cynical but that would make perfect sense to me. The conversation always goes along the lines of "the dogs don't lie, if it alerted then you have something." They say this repeatedly expecting you to back down and sing like a canary.
Invite them to go through your luggage and their faith in the dog evaporates.
Handy tips there probably for actual FlyerTalk narcotics smugglers