Dogs can better detect Covid in humans than lateral flow tests, finds study

Dogs are better at detecting Covid-19 in humans than many fast lateral flow tests (LFTs), according to a French study which could see canines more widely deployed for mass virus screening in crowded places including airports.

The trial, conducted in March and April by France’s national veterinary school and the clinical research unit of Paris’s Necker-Cochin hospital, showed dogs were able to detect the presence of the virus with 97% accuracy.

The dogs were also 91% correct in identifying negative samples, the study showed. A recent review of 64 studies found LFTs correctly identify on average 72% of people infected with the virus who have symptoms, and 58% who do not.

“These results are scientific confirmation of dogs’ capacity to detect the olfactory signature of Covid-19,” the Paris hospital board said, adding that the study – which is due to be published in a scientific review – was the first of its kind.

“These are excellent results, comparable with those of a PCR test,” Prof Jean-Marc Tréluyer told Agence-France Presse. Tréluyer said dogs would not replace polymerase chain reaction (PCR) tests, which are significantly more reliable than LFT tests.

But, he said, “they could help identify those people who should undergo a full viral test and – because the dogs’ response is so quick – facilitate mass testing” in places such as airports, train stations and concert venues.

In the French study, researchers collected samples – cotton pads pressed for two minutes under participants’ armpits – from 335 people aged between six and 76 who presented themselves for a PCR test at testing centres in Paris.

The pads were then sealed in jars and given to at least two of the nine dogs used in the trial – none of whom came into contact with the volunteers – to be sniffed. The dogs’ handlers did not know in advance which samples were positive.

The dogs detected 97% of the 109 people whose PCR test subsequently proved positive, and 91% of those whose PCR test was negative.

Researchers in countries including Australia, Germany and Britain have experimented with dogs to detect Covid, while Finland and the United Arab Emirates last year launched trials with sniffer dogs at Helsinki and Dubai international airports.