Two dogs could accurately scan 300 plane passengers in about half an hour as part of a rapid screening strategy, said scientists from London School of Hygiene and Tropical Medicine. Then only the people selected by the dogs would need to undergo a PCR test.
There is growing evidence that dogs can identify Covid patients in much the same way they sniff out bombs, drugs or other diseases.
Pathogens produce unique volatile organic compounds released by ailing cells. These signature smells could be used to fight outbreaks earlier on in future, the researchers said. The approach, they said, was fast, cheap and non-invasive.
If Covid-sniffing dogs were to be used, it would make a "huge difference", said Dr Claire Guest, co-founder of Medical Detection Dogs.
"The PCR test is gold standard but it's very time-consuming and not feasible in situations where you've got a large number of people moving through," she told the BBC.
"What the dog does is a rapid screen test that identifies those individuals that need a test or isolation."
Covid canines can detect low viral loads
The dogs used in the study were trained to identify Covid using body odour samples on 3,500 masks, socks and T-shirts.
Dr Guest said the tests produced "remarkable results" and were more accurate than the lateral flow tests being widely used across businesses and schools.
Even more remarkably, the finely tuned canines were able to pick out individuals who had a very low viral load.
The research is yet to be peer-reviewed, but Dr Guest regretted that authorities were yet to engage seriously with using dogs in real-world settings.
"It's incredibly frustrating as this is something that could change things rapidly but I think there's always scepticism when the dog is the biosensor," she said.
She acknowledged there are issues around scaling up the use of dogs but said these issues could be overcome by strategic placements "in situations where you know that there's a big risk of identifying positive individuals", thus "significantly protecting the UK from new variants".