“Drug dogs are trained on drugs, and cadaver dogs are trained on cadaver,” says Mary E. Cablk, a scientist at the Desert Research Institute in Nevada who studies scent detection. Training a cadaver dog requires regular contact with human blood, decaying flesh and bones. In the United States, dog handlers can legally obtain bodily components like human placenta and blood, but not always easily, and trainers like Cablk often resort to using their own blood. Some substitute commercially available ersatz odors (the most common is Sigma Pseudo Corpse Scent, which comes in three kinds: recently dead, decomposed and drowned). But deceased humans produce unique volatile organic compounds, and canines have a keenly attuned sense of smell, so you should practice on the real thing. “You don’t want to put other people at risk,” Cablk says — searches are often in dangerous areas, like collapsed buildings — “to find what is ultimately a dead pet.”
Cablk works about 30 cases a year with sheriffs’ departments in California and Nevada, accompanied by her two cadaver dogs. You don’t want a really smart animal, she says; its curiosity might lead to distraction. Instead, look for a midsize dog that never tires of playing with a tennis ball or pull toy. Eventually, you will teach the dog to associate the smell of death with its toy by making the toy smell like death. Your dog should be exposed to, and trained to find, all sorts of dead bodies — on varied terrain, day or night, rain or shine. “You have the whole gamut, from old dry bones to somebody who dropped dead from a stroke an hour before you showed up,” Cablk says. Until proved otherwise, every area is a crime scene. Coach your dog to calmly sit or lie down when it locates a scent’s source. Digging, peeing and frolicking can destroy evidence.
Because most cadaver dogs are deployed by volunteer handlers, establish relationships with local law-enforcement officers if you hope to get your dog out on a real case. Cablk says cadaver-dog handlers should also be physically fit, able to pass background checks, skilled with maps and GPS, unafraid of the dark and unperturbed by whatever flavor of death a dog might uncover.