Asher, Kyp, Lexie, Tala, Millie, and Marlow. They might sound like characters in an X-Men film – but they’re far more important than that. These names belong to six dogs who’ve been trained to detect Covid-19 by sniffing it out.
In a new study, which hasn’t yet been peer-reviewed, the dogs were able to sniff out Covid-19 infection with up to 94% accuracy. They could sniff out samples from people who were asymptomatic, as well as those who had low viral loads.
The vision is that one day in the future, they (and a team of fellow canines) could be deployed in public places, such as airports and sports stadiums, to identify people who have the virus – including those who don’t show symptoms.
Historically, dogs trained at the Medical Detection Dogs HQ in Milton Keynes have detected a range of diseases including cancer and Parkinson’s. They can do this because of their heightened sense of smell – it’s thought 30% of the dog’s brain is dedicated to analysing odour and the percentage of a dog’s brain devoted to analysing odours is 40 times larger than that of a human.
The findings of the study are based on six dogs who tested more than 3,500 odour samples donated by the public and NHS staff. The training method used is reward-based: dogs are given a treat or get to play a game when they make an accurate assessment, so they feel encouraged to detect it again and again.
The dogs were able to identify infections caused by the coronavirus strain that was dominant in the UK last summer as well as the so-called Kent variant (B117) which appeared later in the year.
Professor James Logan, head of the department of disease control at London School of Hygiene and Tropical Medicine (LSHTM), who led the project, told PA Media: “What was great was the dogs that have been trained on the original variant transferred to the new (Kent) variant. They could detect the new variant without any additional training. So this gives us real hope and really suggests that dogs are able to detect different variants of Covid.”
The dogs recruited were a mixture of spaniels and Labradors – and there’s a reason for this. “All dogs and breeds have the capability to detect cancer, other diseases and crisis situations in humans,” the charity’s CEO and co-founder, Claire Guest, told HuffPost UK earlier this year.
“However, because our dogs screen samples on a carousel, we select breeds with a high hunt drive – the kind of dogs that chase a tennis ball 100 times and don’t get bored or tired. Our dogs are chosen according to their ability. It is important they have good noses and love searching and hunting for toys.”
The next phase of the trial will test whether the dogs are able to detect coronavirus on real people in real-world settings such as airports and sports events. It’s been suggested two dogs could screen 300 plane passengers in half an hour.
Scientists believe a combination of specially trained dogs, along with a confirmatory PCR test, could help detect more than twice as many cases and halt onward transmission, when compared to isolating symptomatic individuals only, or testing people with a lateral flow test and a PCR test.
Professor Steve Lindsay, from the department of biosciences at Durham University, said: “This is a very exciting result showing that there is a distinct smell associated with Covid-19 and, more importantly, that trained dogs can detect this with a high degree of accuracy.
“Dogs could be a great way to screen a large number of people quickly and preventing Covid-19 from being reintroduced into the UK.
“Trained dogs could potentially act as a fast screening tool for travellers, with those identified as infective confirmed with a lab test. This could make testing faster and save money.”
“Rapid screening of high numbers of people, even if asymptomatic, will help return our lives back to some sort of normality.”
Trained dogs could also help assess the prevalence of disease among travellers from specific locations including current ‘hotspots’, Professor James Logan, head of the department of disease control at London School of Hygiene & Tropical Medicine, previously said.
“For example, using detector dogs at airports could help establish that 50% of passengers on a plane from destination A have the virus, whereas only 5% of passengers from destination B do,” he said. “This would provide rapid information of risk and likelihood of rapid spread.”
The trial could “revolutionise” how the virus is diagnosed, Prof Logan added. “Rapid screening of high numbers of people, even if asymptomatic, will help return our lives back to some sort of normality.”