Animals, Health

Sniffer Dogs Could Help Stop The Spread Of COVID-19

A cocker spaniel, one of the breeds of dogs best suited to become a sniffer dog, capable of detecting COVID-19 through smell. The others are Labrador retrievers and golden retrievers. Image: Wikimedia Commons.

We may soon have a new way to help wipe out COVID-19: sniffer dogs.

Researchers believe some dogs can be trained to sniff out people who have the virus. Tests are being done in a number of countries including the United States, Thailand, France and the United Kingdom.

If dogs turn out to be good at smelling COVID-19, they could be used in crowded places like airports and sports stadiums to find people who might be carrying the virus. The person would then be tested to confirm they actually do have it.

Identifying people with COVID-19 as early as possible helps ensure they don’t spread the virus to other people.

How do dogs smell COVID-19?

When someone has COVID-19, their breath and sweat produce a certain odour, even when the person doesn’t have any symptoms of the virus. To train dogs to detect the virus, handlers use cotton balls, t-shirts or socks that have absorbed sweat from the armpits or feet of infected people. When a dog smells the sample, it is taught to respond by sitting or pawing at the ground. (The dog cannot catch the virus.)

Dogs are given samples with and without the virus to see if they can tell which ones have it and which ones don’t. The dogs sniff people to see if they can tell who is wearing a t-shirt with the scent of the virus.

Dogs have about 300 million “scent receptors” in their noses. Humans only have about 5 million. Dogs can smell lots of things that humans cannot. (Scent receptors are special hairs and membranes in the nose that detect odours.)

Most of the dogs in the research studies are able to detect the virus accurately about 94 percent of the time.

If enough dogs can be trained to sniff out COVID-19, they could help control the spread of the virus.

Sniffer dogs are as fast–or even faster–at finding COVID-19 than the medical tests we use now. They are also very accurate. Not only that, but using dogs costs less than using medical tests. Sniffer dogs could be especially useful in low-income countries.

Sniffer dogs are now being tested in airports around the world, including Lebanon, Finland and the United Arab Emirates. They have also been used in the United States at events like basketball games and a food festival. One day they could be used in schools, banks, prisons and shopping malls.

It takes about two months to train a dog to sniff out the virus. Researchers have found that the best breeds for the work are Labrador retrievers, golden retrievers and cocker spaniels. Those breeds have about 350 million scent receptors, and a natural instinct for searching and hunting.

Sniffer dogs are already used to help police find illegal drugs, guns or explosives. Some dogs are also able to detect diseases like diabetes, malaria or cancer in people.


Dogs smelling a virus– even when the person has no symptoms? It sounds like fake news, but it’s not. It’s true. What research would you do to confirm that this story is real and not fake? What else tells you it’s real?

Why is it important that COVID-19 is identified as early as possible?

Once a sniffer dog identifies someone with COVID-19, what do you think would happen next?

Most dogs have more scent receptors in their nose than humans. This allows them to smell things we can’t. Think about the other senses: taste, touch, sight and hearing. How do humans compare to dogs or other animals?

Why are Labrador retrievers, golden retrievers and cocker spaniels best suited to becoming sniffer dogs?


Why can’t dogs catch COVID-19? Read this article on The Conversation website to find out more about dogs and other animals and COVID-19.

This website outlines the study:

Meet six of the sniffer dogs who are being trained: Millie, Kyp, Lexi, Marlow, Asher and Tala

France’s COVID-19 Sniffer Dogs

How Dogs “see” with their noses