A group of Australian drug sniffing dogs was accidentally trained using talcum powder instead of cocaine as the discriminative (target) stimulus. Reports indicate that police authorities accidentally supplied a bag of talc instead of cocaine. The mistake was not caught until after the dogs were delivered. (BBC News)

Sniffer dogs are trained using stimulus discrimination conditioning methods derived from research on operant conditioning by B.F. Skinner. In standard discrimination training, the basis of odor detection, a reinforcer is delivered to the dog when it responds to the target scent stimulus while responses to other scents are ignored. With appropriate training, the dogs can detect the target odor among many other stronger non-target odors. Other important elements of sniffer dog training, such as establishing search patterns and ignoring distractions in search environments, are also established using operant conditioning methods. The Canine and Detection Research Institute (CDRI) at Auburn University has done extensive research and development of these techniques. (Read more about it)