Dogs on the Job

Americans love dogs, and we love telling stories about them. For years, dogs have entertained us with their intelligence and charm. Early on, troupes of costumed, performing dogs came into fashion, dancing, playing cards, and acting out "dog dramas" on stage. They eventually found a place in popular circuses, performing tricks and routines.

Any dog that exhibits herding instincts can be trained, and it turns out that herding is a predatory behavior that has been modified from the original predatory behavior through selective breeding of wolves and their descendants. Humans were able to minimize the dog's inclination to look at cattle and sheep as prey, while maintaining their predatory skills.

Search and rescue dogs detect scent, most likely from the scent-carrying skin cells that drop off humans at a rate of 40,000 cells per minute, called skin rafts. Evaporated perspiration, respiratory gases, and decomposition gases released by bacteria on human skin or tissues also probably play a role in a successful search and rescue mission.