Can Dogs Sniff Out COVID-19 Infections? By Heather O'Donoghue

The rapid global spread of Covid-19 in the first half of 2020 has ground the global economy to halt. In order to combat the pandemic, many countries have had to introduce lockdowns that have left many sectors crippled, particularly the hospitality and retail sectors. Governments have had to introduce business relief funds, increase borrowing, and bring in new income protections for those affected. Because of all of this, the UK is pitching towards a deep recession, one that will likely be worse that the financial crash of 2008. It’s not the only country, with the US facing a recession that could be worse than the Great Depression of 1929. It’s obvious that something needs to be done to get economies back up and running. But, without a vaccine or an effective treatment, opening up countries will likely lead to a huge spike in cases and overwhelmed healthcare systems.

Current testing for the virus is not sufficient for a number of reasons. First is limited testing capacity, which means only certain people are eligible for a test. Secondly, the test may not always be effective, and it performs most accurately when done within three days of symptoms developing. Finally, it takes 72 hours to get the results back. The government are therefore looking for alternatives, and have recently purchased, and are planning to deploy, antibody tests developed by Roche Pharmaceuticals and Abbot Laboratories. These tests can tell you whether you have already mounted an immune defence – by producing antibodies to the virus – which indicates you’ve been infected and are protected to a degree from the virus. This is useful information for each of us and our individual health but won’t solve the problem of active, asymptomatic cases – the silent spreaders.

What if we could identify people who have the virus but are asymptomatic, without a time consuming test? Dogs may hold the answer to this extremely important question. The government have provided £500,000 in state funding to a trial that aims to determine whether man’s best friend can sniff out the infection. The trial is being run by the charity Medical Detection Dogs. Six of their dogs will be involved – a mixed group of Labradors and cocker spaniels. Over a period of six to eight weeks, the dogs will be shown samples from NHS workers – some of whom are infected and some who are not. The samples may take different forms, including body odour from clothes or breath from used face masks. Their handlers will gather data on how accurately they can detect the scent of an infected sample to see whether there is value in moving the trial onto the next phase.

Why do Medical Detection Dogs believe that their dogs may be able to sniff out the virus? Dogs are known to have an exceptional sense of smell – they can smell odours in as little as a few parts per trillion. It is thought that the area of their brain dedicated to analysing scents is up to 40 times larger than that of a human’s. Research has shown that dogs have already been successfully trained to identify malaria infections in children by smelling their nylon socks. Some early peer reviewed research has shown that with very particular and intense training, dogs can detect a number of different cancers from a variety of bodily fluids. Trials are underway to determine whether they can reliably detect Parkinson’s Disease before symptoms even develop. This suggests it is not unreasonable to suspect they may be able to smell Covid-19 as well.

It’s not yet clear where the dogs would be deployed if the trial is successful. Medical Detection Dogs estimate that the dogs could check up to 250 people an hour for the infection. This could help to prioritise people for testing at testing centres or improve the testing capacity, depending on how reliable the results are. Another option is to deploy them at airports, train stations, and ports where they might identify people travelling into or around the UK who are likely to spread the virus. We’re all used to seeing dogs at the airport. Usually they are there to look for illegal drugs, money, or other contraband – though sometimes they accidentally find less dangerous items like sausages and cheese. It seems like a natural place for them to seek out Covid-19 infections.

The Home Office are announcing this week that those travelling into the UK from abroad will be forced to self-isolate for a minimum of two weeks regardless of whether or not they display symptoms. This will likely curtail international travel significantly and makes it all the more urgent to find a way to identify asymptomatic carriers so that isolation is only required of those who actually pose a threat. These dogs may offer a way for life to get back to something resembling normal as safely as possible.

References:

Bank of England warns of sharpest recession on record: https://www.bbc.co.uk/news/business-52566030

I.M.F. Predicts Worst Downturn Since the Great Depression: https://www.nytimes.com/2020/04/14/us/politics/coronavirus-economy-recession-depression.html

UK 'absolutely' preparing for second Covid-19 peak and may not see back of virus for 'several years’: https://www.itv.com/news/2020-05-18/dominic-raab-leads-the-government-s-daily-coronavirus-press-conference/

Coronavirus test result: How long to get your coronavirus test results back?: https://www.express.co.uk/news/uk/1275018/Coronavirus-test-result-How-long-for-coronavirus-test-results-time

Coronavirus: NHS antibody tests from next week - but uncertainty over COVID-19 immunity: https://news.sky.com/story/coronavirus-free-antibody-tests-to-be-available-on-nhs-after-deal-made-with-roche-government-says-11992225

Coronavirus: Trial begins to see if dogs can 'sniff out' virus: https://www.bbc.co.uk/news/uk-52686660

Dogs' Dazzling Sense of Smell: https://www.pbs.org/wgbh/nova/article/dogs-sense-of-smell/

The Dog’s Nose: https://www.medicaldetectiondogs.org.uk/the-dogs-nose-2/

UK researchers hope dogs can be trained to detect coronavirus: https://www.theguardian.com/science/2020/may/16/uk-researchers-hope-dogs-can-be-trained-to-detect-coronavirus

Cancer-Sniffing Dogs: Where Are We Today?: https://www.americanveterinarian.com/news/cancersniffing-dogs-where-are-we-today

Dogs to be Taught to Sniff Out Parkinson's: https://www.cureparkinsons.org.uk/news/dogs-to-be-taught-to-sniff-out-parkinsons

Airport sniffer dogs find 'cheese and sausages' but no Class A drugs: https://www.bbc.co.uk/news/uk-36041316

Coronavirus: What are the UK travel quarantine rules?: https://www.bbc.com/news/amp/explainers-52544307