Image credit: Chewy
The Study
Studies in France and Germany showed that dogs could detect Covid-19 in humans. This is laying the groundwork for sniffing dogs in a collective effort to combat the pandemic.
A growing amount of evidence from researchers and dog trainers shows that dogs can detect Covid-19 infections by utilizing their extreme sense of smell. They can even detect it in people who seem to have no symptoms of the virus.
Dogs can do it with a high degree of precision because they have more than 300 million smell receptors. Humans have roughly five million. Dogs can detect compounds released by the human body such as sweat and saliva.
Dogs have often been used to recognize odors involved in dealing with narcotics or explosives and can also detect cancer, malaria, and diabetes. However, this is the first time that dogs have recognized viral infections in humans.
The Results
Dogs were able to detect the existence of the virus with 97 percent accuracy. The trial was performed by France’s national veterinary school at Paris’s Necker-Cochin hospital in March and April.
These results show how good the dogs were at identifying positive samples. The sniffing tool was 91 percent accurate and reflected how well the dogs could detect negative samples. Often 15-minute antigen tests have a more inadequate detection threshold and are more effective at ruling out the infection than catching it.
Image Credit: Jakayla Toney
Virus-sniffing dogs, like those used to detect drugs or explosives, could be used more broadly in airports, train stations, and other places where crowds assemble to screen people.
Researchers obtained samples of 335 people aged six to 76 who offered themselves for a PCR test at testing centers in Paris. They used cotton pads compressed for two minutes underneath the participants’ armpits. Sweat samples obtained from the participants’ armpits were provided to at least two separate dogs for smelling. None of the dogs had encountered the participants before. A total of 335 individuals were tested, with 109 testings positive in a monitored PCR test. The researchers had no idea which samples would test positive ahead of time.
Image Credit: Annie Spratt
Conclusion
In France, the study showed that dogs’ detection rates were 97% sensitive and 91% specific. These results are much better than 15-minute antigen tests. Specificity indicates how easily you can identify a negative sample as a negative. Antigens are samples in blood or urine that trigger an immune response. Sensitivity is how easy it is to identify positive samples as positive. These results are especially impressive when you consider how difficult it is to detect the disease from just one blood sample.
Clinicians in Australia, Germany, and the United Kingdom have used dogs to identify Covid. Finland and the United Arab Emirates have been initiating sniffer dog trials at Helsinki and Dubai international airports since last year.
