Conquering Covid-19 needs rigorous testing. Indeed, testing-on-arrival is key to travel policy in most jurisdictions now; Maharashtra still requires incoming travellers, even domestic ones from a few states, to undergo RT-PCR testing. Such screening, of course, has its own challenges ranging from the additional spending incurred to managing accommodation for travellers in the interval between testing and results being reported. It may seem a little hard to believe, but sniffer dogs may offer a solution. If research bears out preliminary observations from the deployment of dogs to sniff out Covid-19, then canines could reasonably be expected to supplement, if not entirely replace, testing kiosks at airports. Trials in Lebanon, the UAE and Finland have returned promising results. In Lebanon, dogs screened 1,680 passengers and detected 158 Covid-19 cases that were later confirmed by PCR tests. The test results showed that the canines identified negative cases with an accuracy of 100%, and positive cases with 92% accuracy.
A dog’s nose bears 300 million receptors compared to a human’s 5-6 million. But there is no clarity yet on how they are able to catch the smell of Covid-19 so accurately. Though Nature reports that none of the studies presenting dogs as Covid-catchers have been peer-reviewed yet, dogs’ olfactory capabilities have been reported to help in detecting diseases like Parkinson’s and Alzheimer’s. Research published by German scientists found canines could identify 83% of the positive cases and 96% of negative cases from samples taken from the mouths and windpipes of individuals, but the sample size was small. Once scientists can zero in on how dogs can detect SARS-CoV-2 infection, it can transform surveillance. While RT-PCR tests would still be required for confirmatory tests, dogs can help with early detection and containment.