Sniffer dogs for covid

 From The Conversation.

What does a pandemic smell like? If dogs could talk, they might be able to tell us.

We’re part of an international research team, led by Dominique Grandjean at France’s National Veterinary School of Alfort, that has been training detector dogs to sniff out traces of the novel coronavirus (SARS-CoV-2) since March.

These detector dogs are trained using sweat samples from people infected with COVID-19. When introduced to a line of sweat samples, most dogs can detect a positive one from a line of negative ones with 100% accuracy.

Across the globe, coronavirus detector dogs are being trained in the United Arab Emirates (UAE), Chile, Argentina, Brazil and Belgium.

In the UAE, detector dogs – stationed at various airports – have already started helping efforts to control COVID-19’s spread. This is something we hope will soon be available in Australia too.

Our international colleagues found detector dogs were able to detect SARS-CoV-2 in infected people when they were still asymptomatic, before later testing positive.

When it comes to SARS-CoV-2 detection, we don’t know for sure what the dogs are smelling.

The volatile organic compounds (VOCs) given off in the sweat samples are a complex mix. So it’s likely the dogs are detecting a particular profile rather than individual compounds.

Sweat is used for tests as it’s not considered infectious for COVID-19. This means it presents less risk when handling samples.

To properly train a dog to detect SARS-CoV-2, it takes:

6-8 weeks for a dog that is already trained to detect other scents, or

3-6 months for a dog that has never been trained.Could the dogs spread the virus further?

Dogs in experimental studies have not been shown to be able to replicate the virus (within their body). Simply, they themselves are not a source of infection.

Currently, there are two case reports in the world of dogs being potentially contaminated with the COVID-19 virus by their owners. Those dogs didn’t become sick.

To further reduce any potential risk of transmission to both people and dogs, the apparatus used to train the dogs doesn’t allow any direct contact between the dog’s nose and the sweat sample.

The dog’s nose goes into a stainless steel cone, with the sweat sample in a receptacle behind. This allows free access to the volatile olfactory compounds but no physical contact.

Furthermore, all the dogs trained to detect COVID-19 are regularly checked by nasal swab tests, rectal swab tests and blood tests to identify antibodies. So far, none of the detector dogs has been found to be infected.