Sniffing Out COVID-19

What’s not to love about dogs? From their playfulness to their protectiveness, dogs have shown that they truly are man’s best friend. During COVID-19, we may need dogs more than ever, and not only to keep us company. What people may not know is they can also detect disease. With their acute sense of smell, they are now the watchdogs of disease. Dogs’ powerful sense of smell enables them to detect many diseases, including various cancers, diabetes, Parkinson’s and now COVID-19.

The sensitivity of a dog’s nose overwhelmingly surpasses that of a human’s, containing around 60 times more scent receptors, which are located in the nose. They can use their powerful noses to smell volatile organic compounds which are gases produced by bodily fluids. These specific gases can alert a canine to the presence of a disease. Dogs can even be trained to alert people to the presence of a specific disease, like COVID-19. 

Dr. Cynthia Otto, Professor of Working Dog Sciences and Sports Medicine at the University of Pennsylvania’s School of Veterinary Medicine, works firsthand with dogs trained to sniff out COVID-19. Dr. Otto explained the process is similar to the way a dog is trained to recognize any odor, just much more complex due to the vast differences among human odors, which are influenced by a variety of factors including diet and age. 

The process begins with a dog smelling the shirt of someone who has COVID-19. This sniffing is followed by a clicker sound, which is a noise that represents that the action will be followed by a reward. The dogs eventually understand the reward process and will only alert to the positive COVID-19 cases. 

So, will dogs start replacing testing sites? According to published research, COVID-19 sniffing dogs can identify a positive case 94% of the time. However a regular COVID nasal swab test is even more sensitive than COVID-sniffing dogs. A test with high sensitivity will be able to detect anyone who is positive almost 100% of the time, without creating many false negative results. Due to the immediacy and ease of obtaining these results, mainstream use of COVID sniffing dogs could become as common as airport bomb and drug detection dogs. 

There are a couple caveats, however. “It is a lot harder to train the dogs on COVID than it is on bombs. It would require a lot of dogs to actually make an impact,” says Dr. Otto. 

Mainstream use would also require the dogs to be regularly tested in order to ensure they are still smelling effectively.

In addition, Dr. Otto said, “As far as we know, the different variants [of COVID-19] are similar enough in odor that the dogs are able to detect the samples from people who are infected.” 

Despite the work it requires to use COVID sniffing dogs, many places where people gather in large numbers, such as the FTX Arena, home of the NBA’s Miami Heat, have begun to use COVID sniffing dogs to screen people. 

There is definitely a place for dogs in the world of COVID-19. While dogs may not be as sensitive as genetic COVID tests, they are accurate enough to ensure an extra level of protection. The fight against COVID-19 has been, and will continue to be challenging, but with the help of our furry friends, it may just get a bit easier.