Dogs Are the Most Reliable and Fastest Coronavirus Detectors

It is nothing new that dogs have a much more developed sense of smell than humans. They have about 300 million olfactory receptors, compared to our body’s dedicated 6 million olfactory receptors. A third of their brains are responsible for analyzing smells, compared to 5 percent of our brains. “They could detect the equivalent of a single drop of liquid in 20 Olympic-sized swimming pools. That’s about three orders of magnitude better than scientific instruments,” said Professor Tommy Dickey, one of the authors of the analysis. That’s why they’re used to detect conditions like malaria, diabetes, certain types of cancer, epilepsy and Parkinson’s. With the outbreak of the 2020 outbreak, they also began to study whether the coronavirus could be detected. As early as July of that year, research by the University of Hannover showed that their success rate was very high, reaching 94%, which was comparable to the success rate of PCR.

sniffing for biomarkers

The delicacy of the dog’s scent goes a step further. They were even able to detect the respiratory virus in presymptomatic and asymptomatic patients whose viral loads were too low for traditional tests to be useful. And, according to Dickey, “even within infected organisms, they could distinguish SARS-CoV-2 and its variants from other respiratory viruses such as the common cold or flu.”

Until just over a year ago, people didn’t know exactly how they did it. In March 2022, researchers at Florida International University proposed that infected people release specific substances called volatile organic compounds (VOCs), which can be detected by trained dogs. They trained four dogs to wear masks from infected patients and others who tested negative, and they successfully learned to detect biomarkers that would reveal the presence of the new coronavirus. After 40 trials, the success rate was greater than 95% for all dogs. The most accurate was Cobra, a Belgian Malinois with 99.4 percent accuracy. It was followed by Dutch Shepherd One Betta with a score of 98.1%. Hubble (Border Collie mix) achieved 96.3% and Mac (Terrier mix) achieved 96.2%.

at the airport, even on the street

In the Basque Country, a project was also launched in 2021 to train dogs for this purpose. It’s called Covid K-9. A kit was sent to infected people to collect sweat samples, identify molecules that would reveal the presence of the coronavirus, and isolate them, enabling the animals to be trained.

Effectiveness is not the only advantage. So is time. The rapid test takes 15 minutes, compared with seconds if the dog sniffs the patient directly, or minutes if the dog is given a sweat sample. Furthermore, as the American University researchers emphasize, they are less invasive than nasal swabs and eliminate environmental pollution caused by single-use plastics.

“Following a comprehensive review, we believe dog tracking is worthy of use as a serious diagnostic method, particularly useful during future pandemics, possibly as part of rapid health screening in public places,” the meta-study authors explain. Australia, Finland Countries such as the United Arab Emirates, Chile, Argentina, Brazil and Belgium already use them at their airports. “Police dogs can also be used for street patrols to spot asymptomatic people,” says Xabier Guruceaga, a microbiologist at the UPV/EHU’s Fungal Biology Unit, who is one of the heads of Covid K-9.