It’s no secret that dogs are incredibly smart and sensitive animals; for decades they have been more than just the average household pet. They're used as guides for people with disabilities, security for households, and aids to the police and medical professionals when detecting certain diseases, drugs and bombs. Following up on that last point, dogs have been known to detect Cancer, Malaria, Parkinson’s and most recently, have been trained to sniff out COVID-19.
Why are dogs so good at sniffing out diseases? Compared to humans, dogs have more than 50 times the number of smell receptors we have, at 6 million and 300 million respectively. These receptors are excellent at picking up tiny volatile organic compounds (VOCs) that cause “various diseases such as ovarian cancer, bacterial infections, and nasal tumours” and are found in bodily fluids and breath (Penn Vet, 2020).
How does this work with COVID-19? Scientists are still unsure, but they predict that because COVID also enters the bloodstream and other organs, the scent of urine would differ to that of a healthy person.
Across the world in places like the United States, Finland, and Great Britain, studies have commenced the training for dogs to detect COVID-19 using samples of urine from individuals who are carrying the virus and those who are not—with very promising results. At University of Helsinki in Finland, after just a few weeks, the dogs were successfully completing this task “almost as [accurate as] a standard PCR test” (Freund, A, 2020).
The University of Pennsylvania’s School of Veterinary Medicine also ran trials in May, using 8 dogs with both urine and saliva samples. The German Assistance Dog Center (TARSQ) in Germany, the London School of Hygiene and Tropical Medicine and Durham University in the United Kingdom have also begun their research with hundreds of thousands of funding money.
There has to be a double blind study before this can be applied to the real world—meaning a test where the dogs are given samples in which the researchers are unsure of COVID presence (and the sample gets tested after). Once tested, applications include airports, big crowds at events, and the action of smelling out rooms before humans enter. Obviously dogs will not be replacing the official tests run by the government but they can help cover areas where tests cannot be administered for everyone.
When working with animals in this way, there will always be some understandable skepticism and concern. "No one could tell us with certainty whether training with the aggressive virus is dangerous or not for humans and dogs” says Luca Barrett, the founder of TARSQ. There have been cases of dogs contracting the virus, so researchers must work carefully. Additionally, training dogs to sniff out cancers has been a concept for years and is still widely rejected by certain doctor, so it’s unlikely we’ll see this take over any time soon. Researchers are also still unsure about how accurate dogs can detect the virus at various stages in the incubation period.
This video gives you an idea on where the progress is and how training works, give it a watch if you're still uncertain with this experiment.
Whether or not dogs end up working in official settings to sniff out the virus, humans will always be proud and impressed by their progress. It is interesting to see how dogs have so many smell receptors and can be trained to obtain such results. What other animals could follow their lead?
Article Contributors: Linda Duong, Edie Whittington