Coronavirus sniffer dogs on patrol at Helsinki Airport
Finland has deployed coronavirus-sniffing dogs at its main international airport in a four-month trial.
It is hoped the alternative testing method could become a cost-friendly and quick way to identify infected travellers.
Four dogs of different breeds trained by Finland's Smell Detection Association started working on Wednesday at Helsinki Airport as part of the government-financed trial.
Anna Hielm-Bjorkman, a University of Helsinki professor of equine and small animal medicine, said: "It's a very promising method. Dogs are very good at sniffing.
"If it works, it will be a good screening method at any other places."
She listed hospitals, ports, elderly people's homes, sports venues and cultural events among the possible locations where trained dogs could put their noses to work.
While researchers in several countries, including Australia, France, Germany the United States, are also studying canines as coronavirus detectors, the Finnish trial is among the largest so far.
Ms Hielm-Bjorkman said Finland is the second country after the United Arab Emirates - and the first in Europe - to assign dogs to sniff out coronavirus.
A similar programme started at Dubai International Airport over the summer.
Passengers who agree to take a free test under the voluntary programme in Helsinki do not have direct physical contact with a dog.
They are asked to swipe their skin with a wipe, which is then put into a jar and given to a dog waiting in a separate booth.
The participating dogs - ET, Kossi, Miina and Valo - previously underwent training to detect cancer, diabetes or other diseases.
It takes the dog 10 seconds to sniff the virus samples before it gives the test result by scratching a paw, laying down, barking or otherwise making its conclusion known.
The process should be completed within one minute, according to Ms Hielm-Bjorkman.
If the result is positive, the passenger is urged to take a standard PCR coronavirus test to check the dog's accuracy.
Timo Aronkyto, the deputy mayor of Vantaa, the capital region city where the airport is located, said the programme is costing 300,000 euro (£319,000) - an amount he called "remarkably lower" than for other methods of mass testing of arriving passengers.
The four sniffer dogs are set to work at the airport in shifts, with two on duty at a time while the other two get a break.
Anette Kare, of Finland's Smell Detection Association, explained: "Dogs need to rest from time to time.
"If the scent is easy, it doesn't wear out the dog too much. But if there are lots of new scents around, dogs do get tired easier."