Can You Really "Smell" Death?

Most of us probably can't, but it's What the Dog Knows

When I was four years old, I lived with my mother and grandparents in a white house with two porches. I remember a day in spring, when little bluebells were blooming next to the front steps, I began thinking of each little bell as the life of a person. How long would it live? Fifty years? Maybe I even guessed a hundred. But the point is this: I worried about what would happen when the bluebell’s life was all used up. What happened then? The real question, of course, was what happens when you die? In my confused ideas about bluebells, I had grasped that no matter what, no living thing would stay the same. Change happened. Nothing was permanent. Not even the people I loved. Not even me. Process meant change, and change meant dying. But at what point does dying become death? Can we recognize it? Can we smell it?

In 2010, a a Belgian graduate student, Elien Rosier, started putting tissue samples and organs from dead animals and six autopsied corpses in jars in a lab closet. Not just for fun, either. She worked with analytical chemist Eva Cuypers in the toxicology lab of the University of Leuven. Rosier collected compounds from the gases emitted, 452 in all, and noticed something deeply intriguing. The jars contained human as well as animal remains, but the smell of death wasn’t the same for each. As it turns out, eight compounds distinguished pig and human remains from those of other animals, and five allowed researchers to differentiate pigs (who are quite similar to us in general) from human beings. The exact “smell” still hasn’t been completely isolated, but we know there is one—and that human death may even be distinct. But of course, in this case, we are talking about the putrescent dead. The smell of decay. What about the newly dead? What about the not yet dead?

Oscar the cat and Scamp the dog—both companion animals at different nursing facilities—found there way into headlines for “detecting” or even “predicting” death. Oscar, a mottled white-and-striped tabby, would snuggle up to individuals in the hours before they died, with a reported success tally of 50 “correct calls.” Scamp, an Ohioan like myself, supposedly barked or paced in front of a patient’s room before the end, earning him the unfortunate nickname, “Grim Reaper Dog.” The papers tended to promote the idea that these animals had a particular “gift,” but that gift probably resides in their noses.

Death is rarely if ever simply the event of ceasing to physically live and breathe. It is always things – emotions, states of being, a constant flux of changing relations (even at the cellular level). In other words, death is both an event and a process, and some of that process gets a head start. Some changes to the metabolism can cause the breath, skin and body fluids of the dying to have a smell similar to that of nail polish remover. Certain illnesses, including cancer and even Alzheimers, have an associated smell as well. Joy Milne claims that Alzheimer’s smells of rye bread. She has hyperosmia, an overwhelming sensitivity to smells, and can accurately “test” for Parkinsons, Alzheimers, and Diabetes. Joy is a rarity. Most human beings don’t have the sensitivity or the training. Doctors did once rely much more heavily on smell before modern diagnostics, but with the accuracy of today’s tests, there isn’t much need for a medical nose. That doesn’t mean the smell of death isn’t important to science, however—particularly to forensic science.

Almost 600,000 people going missing in the US every year. Luckily, many are found quickly. When the days lead to months and even years, or when death is presumed or expected, they can’t be located without specialized help. For that, search units rely on dogs; not pets like Scamp, but highly trained “cadaver dogs.”

In May 2013, David Noren, 49, of Lakewood, Colorado, vanished. That wasn’t his style; everyone who new him worried for his safety. After all, he’d abandoned his best friend, a 12-year old Labrador named Olivia. Officers found his car and examined it thoroughly—but not as thoroughly as Radar, a bloodhound trained in identifying human remains. He located droplets of blood: evidence of foul play. Eventually Noren’s murderer (his roommate) would be caught and sentenced. Cadaver dogs have something special in addition to their noses: drive, smarts, a kind of wilfulness that makes them independent (ahem, and sometimes unruly) pets. What they need is the right kind of training. And I know someone who can tell us all about it.

Cat Warren didn’t mean to raise a cadaver dog, but Solo, her German Shepherd, led her (pulling and straining) into the world of forensic search and recovery. In What the Dog Knows, she gives us both the history of the practice (it started when 1970s Army researchers began wondering how bomb-sniffer dogs might perform in peacetime), and her own often humorous journey to turn Solo into a top notch nose. Along the way, she takes us to crime scenes, training sites, and science labs with animal psychologists, forensic anthropologists, and scent researchers.

She also talks about what death smells like to her. It’s not what you think. Against odds, human decay, even with its signature scent, can nonetheless vary from the oddly sweet—to revoltingly gut-turning—to nothing more than wet leaves and earth. You can ask her about it, if you like; she will be joining the Peculiar Book Club on January 26th at 7pm Eastern. The live show is for our Patreons (you can subscribe to chat with her), or catch the show on our YouTube Channel after it airs. (PS: she also has a Young Reader’s Edition for the forensic kids in your life).

In the meantime, I’ll leave you with these six common smells of body decay to ponder:

• Cadaverine and putrescine - rotting flesh

• Skatole - feces odor

• Indole - musty, mothball-like smell

• Hydrogen sulfide - rotten eggs

• Methanethiol - rotting cabbage

• Dimethyl disulfide and trisulfide - foul, garlic-like odor