BANGKOK – Bobby was a good boy. Bravo too.
Angel was a good girl, and when she sat with her furry hindquarters sliding a bit on the tile floor, she lifted a paw for emphasis, as if to say it’s that cotton ball that my sharp nose identified and that smells like COVID -19
“The smell is obvious to dogs, as is grilled meat to us,” said Dr. Kaywalee Chatdarong, Deputy Dean of Research and Innovation at the Veterinary Faculty of Chulalongkorn University in Bangkok.
The hope is that dogs can be used in crowded public spaces such as stadiums or transport hubs to identify people who are carrying the virus. Your skills will be developed in Thailand, France, Great Britain, Chile, Australia, Belgium and Germany, among others. They have monitored airports in Finland, Lebanon, and the United Arab Emirates, and private companies have used them at American sporting events.
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Angel, a pale blonde with beginning cheeks and a penchant for crunching plastic bottles, is the star of the pack at Chulalongkorn University. As a group, the dogs trained in Thailand – Angel, Bobby, Bravo, and three others, Apollo, Tiger, and Nasa – recognized the virus accurately 96.2% of the time in controlled environments, according to university researchers. Studies in Germany and the United Arab Emirates had lower but still impressive results.
Sniffer dogs work faster and far cheaper than polymerase chain reaction or PCR tests, say their proponents. A suction of air through their delicate snouts is enough to identify, within a second, the volatile organic compound or mixture of compounds that are created when a person with COVID-19 sheds damaged cells, researchers say.
“PCR tests are not immediate and give false negative results, even though we know dogs can detect COVID during the incubation period,” said Anne-Lise Chaber, an interdisciplinary health expert at the University of Adelaide’s School of Animal and Veterinary Sciences Australia, who has been working with 15 COVID-sniffing dogs for six months.
Some detection methods, such as temperature screening, cannot identify infected people without symptoms. But dogs can because the infected lungs and windpipe produce a branded fragrance. And dogs need fewer molecules to excrete COVID than are required for PCR testing, Thai researchers said.
The Thai Labradors are part of a research project jointly carried out by Chulalongkorn University and Chevron. The oil company had previously used dogs to test their offshore workers for illegal drug use, and a Thai manager wondered if the animals could do the same with the coronavirus. A dog’s ability to sense COVID-19 is in theory no different from its ability to sense narcotics, explosives, or a Scooby snack hidden in a bag.
The six dogs were assigned six dog handlers, who exposed them to sweat-drenched cotton balls from the socks and armpits of COVID-positive people. Researchers say the risks to the dogs are small: the coronavirus is not known to be easily transmitted through sweat, a commodity abundant in tropical Thailand. Instead, the main route of transmission appears to be respiratory droplets.
On rare occasions, cats and dogs in close contact with infected humans have tested positive for the virus, as have populations of mink and other mammals. (However, there are no proven cases where pets can transmit the virus to humans.)
Within a few months of training, the Thai dogs obediently sat around 600 sniffing a day when they felt the cellular byproducts of COVID-19 on cotton balls that the researchers placed on a carousel-like device at nose level.
Dogs whose wet snouts have up to 300 million olfactory receptors, compared to about 6 million in humans, can be trained to memorize about 10 olfactory patterns for a given compound, Kaywalee said. Dogs can also smell through another organ located between the nose and mouth.
Some research has shown that dogs of different breeds may be able to detect diabetes, Parkinson’s, malaria, and certain types of cancer – that is, the volatile organic compounds or body fluids associated with them.
Labradors are among the smartest breeds, said Lertchai Chaumrattanakul, who leads Chevrons portion of the dog project. They are also sociable, making them the ideal dog detector: dedicated and eager.
Lertchai noted that Labradors are expensive, around $ 2,000 each in Thailand. However, the cotton swabs and other basic dog testing equipment cost around 75 cents per sample. This is much cheaper than what is needed for other types of rapid screening. Last week Singapore announced that it is temporarily approving some kind of breathalyzer to test for COVID-19.
Three of the Thai Labradors are stationed in the deep south of the country near the border with Malaysia, where dangerous COVID-19 variants have entered Thailand according to the Ministry of Health. The other three have been moved to the ninth floor of the Chulalongkorn Veterinary Faculty building in Bangkok in recent weeks, where they live in former student dormitories. There is artificial turf on the roof for quick pit stops, and the dogs frolic on a university soccer field every day. Your rooms are air-conditioned.
In the mornings and afternoons, the retrievers take turns walking up and down for a few hours in a room equipped with metal arms from which sweat samples dangle. They walk by and sniff up to 10 times per second like dogs normally do. (People tend to only take a single inhalation every second or so.)
Then they retreat to their living quarters to take a nap and occasionally rub their tummies.
“Their lives are good, better than many people’s,” said Thawatchai Promchot, Angels Handler who worked as a chevron supplier before turning to animal health screening.
Thawatchai said he grew up with 12 dogs in southern Nakhon Si Thammarat province, where the family’s pets dozed in the garden, looking for shade under trees. They didn’t enjoy air conditioning.
The dogs living in Bangkok are now examining sweat samples from Thais who cannot easily reach COVID test sites such as the elderly or the bedridden. The dog sitters are working to set up a program with the city’s prisons where thousands of inmates have been diagnosed with COVID.
Thailand is suffering from the worst coronavirus outbreak since the pandemic began. Clusters multiply in prisons, construction camps, and other cramped spaces. Vaccines are in short supply and less than 2% of the population have been vaccinated.
Chulalongkorn researchers have developed a mobile unit they plan to use to drive to potential COVID hotspots so dogs can locate areas where mass testing is needed.
There are still many questions about using dogs to detect the virus. How do vaccinated people smell? How easy will it be to train a large group of COVID-sniffing dogs around the world? What if people who are tested with a dog’s nose aren’t that sweaty? What if a dog gets COVID-19 and loses its sense of smell?
Still, Lertchai said he thought virus-detecting dogs would be a boon, especially in countries that don’t have the resources for more expensive testing.
“COVID is not going away and there will be new variants,” he said. “Dogs want to be helpful, so let’s use them.”
This story was originally published on nytimes.com. Read it here.