Corona detection dog Silja

(Egil Björkman/University of Helsinki)

Tired of having a swab shoved down your nose and throat every time you have a cough or need to travel? Well, man’s best friend might be able to help you out with this, too!

We’ve all been amazed by footage of trained canines performing complex tasks on the internet. While it may appear that there is nothing going on behind their lovely little faces, Finnish researchers have discovered that there is more than meets the — well, we have to say it — puppy eyes.

Sniffer dogs have already been employed to detect epileptic fits, cancer and Parkinson’s. But since 2019, researchers have been striving to prove the effectiveness of utilising dogs to sniff out potential COVID-19 patients.

Now, there seems to have been a major development in this quest, as a new study has indicated that trained dogs are exceptionally capable of detecting coronavirus infection among people, boasting a testing accuracy of 92%!

The sniffing process

Scientists from around the world have envisioned that dogs’ extremely well-developed olfactory systems might provide a cheap and reliable approach to effectively screen large numbers of people quickly.

To test this, researchers from the University of Helsinki conducted trials at the Helsinki-Vantaa International Airport in Finland, which reaped some incredible results.

The trials followed a simple process, where arriving overseas travellers were instructed to dab their skin with a wipe after retrieving their luggage. This wipe was then dropped into a container and passed onto the dog and its trainer on the other side of a wall. This ensured that passengers allergic to dogs were taken into consideration and that the trainers were not subjected to the coronavirus.

Subsequently, a trained dog was able to identify the presence of the coronavirus in less than 10 seconds, and the entire process took less than a minute. The dogs were taught what a swab from a COVID-19 infected person smells like, and were instructed to yelp, paw or lie down if they detected the same smell in the sample from a new patient. If the result turned out positive, the passengers were directed to the Helsinki University Hospital’s health information station for further instructions.

This breakthrough is significant because it provides a non-invasive, incredibly fast and inexpensive technique of screening. In India, an RT-PCR test can cost up to and above ₹1000, making it exceedingly inaccessible, especially for travellers who will also have to pay for their large trip fees. One of the researchers even claims that this method will only take 2.5% of the traditional PCR screening costs per month.

Incredible results in real world

These mind-boggling statistics only got better when the dogs were put in a real-life circumstance of sniffing out real passengers and personnel at the International Helsinki-Vantaa Airport in the third stage of the study. The dogs demonstrated an accuracy of 98.7%, some even five days before the COVID symptoms manifested!

On some days, the dogs even boasted success rates of nearly 100%. After sniffing samples in specially prepared cells at the airport, the canines confirmed that 296 of the 300 passengers were COVID-negative on one day.

It is noteworthy that among the four dogs that were trained as sniffers — which included three labrador retrievers and a white shepherd — only minute differences in accuracy were observed, showing that this process is extremely replicable for future training among different species.

Variant detection

These compelling results are only preceded by the fact that most of the error in the judgement of our canines comes due to differences in the coronavirus variant.

“I was particularly impressed by the fact that dogs performed worse with samples we had collected from patients suffering from a disease caused by a coronavirus variant,” said Anu Kantele, Professor of Infectious Diseases and Chief Physician at the University of Helsinki and Helsinki University Hospital.

The explanation is simple:  the dogs had originally been trained with the initial wild-type virus, and thus they did not always identify the variant samples as positive, demonstrating their incredible ability of discrimination, Kantele elaborated.

Will the dogs carry the virus?

The researchers also addressed concerns that the dogs might pass the virus on to humans or other animals, highlighting that there have been no recorded cases of this happening in the past.

According to Anna Hielm-Björkman of the University of Helsinki, while COVID-19 is known to infect mink and cats, dogs lack the receptors required for the virus to get a footing and do not appear to be easily infected.

The training process for the dog takes about 1-3 months. Sometimes, little bonuses such as delectable meatballs and sausages are needed to shake things up and keep the dogs inspired, explained the project manager Soile Turunen of the Wise Nose scent-detection foundation.

Currently, similar projects are being undertaken in Australia, France, Germany, Britain, with Dubai already having started test trials. However, there still remains a need for more peer-reviewed studies in order to determine the full extent as well as the limitations of dogs’ ability to detect COVID-19.

The study was published in the journal BMJ Global Health and can be accessed here.


For weather, science, space, and COVID-19 updates on the go, download The Weather Channel App (on Android and iOS store). It’s free!