While trials and training of dogs to detect the coronavirus have begun in countries like Germany and the UK, Finland is the first country that has put the corona dogs already to work.

Watch an introduction to the work of a corona dog. Video: Vantaakanava

Tony Öhberg contributed to this report.

Corona dogs started working at Helsinki Airport on Wednesday. By Thursday evening, they had identified the first positive samples.

 “We have ten dogs that can reliably work in the airport environment,” Susanna Paavilainen, research coordinator at the University of Helsinki and CEO of Nose Academy, said in a statement.

Here’s how the testing works:

After arriving at the corona dog sampling station, the passenger steps into a small space surrounded by screens, where the passenger takes a skin swipe according to the instructions given and drops the sample into the container provided for it.

The dog and its trainer are behind a wall, where the dog sniffs the given sample. In this way, the allergic passengers and those afraid of dogs are taken into consideration, and care is taken that the trainers are not subjected to the coronavirus. Personal information is not collected at the sampling station. If the result is positive, the passenger is directed to the Helsinki University Hospital’s health information station for further instructions.

In a Tweet on Thursday evening, Timo Aronkyrö, deputy mayor, head of health and social services at City of Vantaa, said that the dogs had already found the first passengers carrying the Covid-19 disease. “The work will continue,” Aronkyrö said.

Currently, four dogs are sniffing the samples. The official status of corona dogs is still being clarified, so civilian dogs are used in the pilot instead of service dogs. Civilian dogs are not being trained for sniffing humans directly.

“Some of the dogs will remain as laboratory dogs, that will sniff samples in very calm circumstances without distractions,” Paavilainen said. “The work shifts of a dog proceed in terms of the dogs’ endurance, so we always have two dogs ready to step in while two others are on a work shift.”

Learning the smell of coronavirus takes from a few hours to a few months. International peer-reviewed studies have shown that a dog’s ability to find positive patients is about 94%–100%, depending on the dog.

Dogs can detect coronavirus from a significantly lower amount of virus than the commonly used PCR tests. (It’s also certainly more pleasant than the nose swab.) This means that a dog will be able to identify the coronavirus in humans earlier than laboratory tests. It has also been found that a dog’s nose has identified coronavirus infection in asymptomatic people days before the onset of coronavirus symptoms. Laboratory tests cannot do this.

In Finland, and around the world, dogs have a long history of being trained to smell certain drugs and even diseases like cancer and Parkinson’s disease.

To find out more about how dogs detect smells, we interviewed Anna Hielm-Björkman, a veterinarian and a researcher at the University of Helsinki.

Björkman told us that in Finland, dogs have been trained to sniff canine and humane breast cancers as well as human prostate cancer. “The best dogs have a sensitivity and specificity of over 90 percent,” she said. This percentage makes them ideal candidates for becoming diagnostic assistants. With a new virus comes a new smell and even though the research is still at its early stages, dogs seem to be able to detect this new scent after only a few weeks.

How are the dogs selected? The research group works with dogs that have already been trained for smell detection by the Wise Nose (Suomenhajuerottely ry). Dogs are then trained to distinguish between Covid-19 positive urine samples from those without the virus. Björkman specified that the positive urine samples don’t contain any living virus and that “dogs do not have the right type of receptors so it is thought that they will not get sick from Covid-19.”

The findings from Finland are some of the first to be gathered. However, other countries like Germany and the UK have started their trials with the hope of getting similar results to those from Finland.