Is there anything that dogs cannot sniff out?

Written by:
Dairy cow, milk

Service dogs in the military are honored for outstanding and heroic actions. They are buried with full military honors when they die. Every now and then, I discover more detective skills that man’s best friend learn in other fields. Candidly, this makes me wonder whether they also receive honors when appropriate.

Dogs German Shepherd


Olfactory receptors allow us to identify different smells. As humans, we are quite proud of our sense of smell, made possible by the six million olfactory receptors we have. Interestingly, dogs could have as many as 300 million olfactory receptors. That fact removes any questions I ever had about why they are outstanding detectives. In fact, I’ve written about a Rookie search-and-rescue dog’s skills who went above and beyond on his first SAR outing. In the light of that,  I want to share some unusual fields in which detecting specific smells makes canines the unsung heroes.

Dogs can detect different cancers

Cancer is one of the medical fields in which dogs are becoming invaluable. For example, a 75-year-old patient went to the doctor to look at an insignificant, small lesion behind his ear. He mentioned that his dog kept licking the lesion. Subsequent;y, tests revealed that the man had malignant melanoma.

Scientists explain that different cancer types produce different odors. Researchers believe that training dogs to identify specific odors could help diagnose cancer before visible tumors form. The Penn Working Dog Center is training dogs for its cancer detection division. Their goal is to use the dogs to identify the different cancers and then develop electronic sensors to screen and diagnose the cancers earlier.

Dogs, Labrador Retriever
Labrador Retrievers trained to smell Coronavirus

Dogs are trained to detect coronavirus

Dogs are already able to distinguish and identify three different types of bovine viruses that cause influenza, herpes and diarrhea in cattle. The same Working Dog Center at the University of Pennsylvania began a training program to teach dogs to sniff out humans with coronavirus. Eight Labradors are the first trainees in the program. The goal is to establish teams of canines for surveillance and screening of hospital patients, travelers and tourists at airports and groups of conference attendees.

Similar training is underway at the London School of Hygiene & Tropical Medicine. Malaria detecting canines now learn to identify the coronavirus, for which scientists collect viral samples from COVID-19 infected patients. The UK government’s intention is to deploy canine surveillance teams at airports to screen and identify coronavirus-carrying travelers that arrive from abroad.

Bed bug detectors

This one I would never have guessed. However, it makes perfect sense. Bedbugs are so small and difficult to see, but dogs’ sniffing powers make them exceptional bed bug detectors. At the University of Florida, dogs were trained to identify the smell of bed bugs as far back as 2008. The training was so successful that the dogs could even discern the different odors of dead and live bedbugs, their eggs, skin and feces.

Cadaver dogs discovered 3000-year-old remains

We are familiar with the jobs cadaver dogs do during searches for people who went missing decades ago. However, there is much more to human-detection dogs. An archaeologist in Croatia and a dog trainer tested dogs’ abilities to uncover centuries-old remains. The archaeologist discovered a fort dating back 3,000 years in a mountain range. The dogs were able to detect human decomposition molecules. They found graves containing burial chests holding human finger and toe bones.

Dogs, Labrador and puppy
Labradors trained to detect people carrying explosives

Dogs can detect people carrying explosives

Invisible to us, thermal plumes surround us all, and trail behind us as we move. Researchers have trained Labradors to use the heat plumes to detect explosives attached to human bodies. Most importantly, the dogs are used to detect explosives in airports and other places with crowds like large concerts.

Burmese Python
Burmese Python

Python detectors

Detection dogs receive training at Auburn University to detect Burmese pythons. Pythons are an invasive species that threaten birds and mammals in the Everglades National Park in Florida. Examples of their detective abilities are Ivy and Jake, two canines that found 19 pythons in the park in 2010. Similarly, another canine team, Floyd and Vito, worked in the Florida Keys, where they sniffed out five Burmese pythons in 2017.

Dairy cow, udder

I kept the best for last

Dairy farmers use dogs to tell them when the time is right for artificial insemination. It is a difficult task that involves the farmers watching the cows’ behavior as an indication of cows in estrus — or fertile. Amazingly, trained canines can identify specific odors in vaginal fluid, blood samples, and urine to indicate the fertile period with over 80% accuracy. In the same vein, when sniffing the milk, the accuracy rate was 99%.

Interestingly, a 2013 study used dogs with experience in narcotics and cancer detection to sniff cow saliva. Their success rate in detecting fertile cows was 60%.

In short, there seems to be no end to the sniffing powers of man’s best friend.

Share THis