“Sniffer dogs” are used for detection of human remains, lost persons, trafficked drugs, explosives, weapons and other illegal contraband.
Many dogs have been trained to detect diseases including Parkinson’s, various cancers, seizures, infections, low blood sugars in insulin-dependent diabetic patients. A dog’s olfactory cortex is reportedly 40 times larger than a human’s, making it capable of storing and recalling vast numbers of scents for many years.
With over 200 million scent receptors in comparison to a human’s five million, a dog’s nose can detect the odour of particular molecules and compounds that alter during disease. These odours are believed to come from Volatile Organic Compounds (VOCs) produced by biochemical changes in the body caused by malignancies, inflammations, infections, and other pathological events, including viral infections such as COVID.
The metabolic changes are detected in breath, sweat, urine and skin. Critical to our efforts to stop the rapid spread of COVID-19 is having an efficient way to identify positive cases and tracing their contacts for purposes of isolation. Nasal swabs and CT scans may be accurate in diagnosing someone with COVID, but they are relatively expensive, require medical equipment, trained staff, time to implement and obtain results. It is suggested that the use of trained dogs leads to earlier detection of infected persons at a lower cost.
Especially useful in situations when large numbers of people need to be screened quickly, a Sniffer Dog trained to detect COVID-19 helps identify asymptomatic carriers quickly. Each well-trained dog has a screening capacity of 250 samples per hour. While there are dozens of COVID-sniffing dogs in Dubai and Miami airports now, Cobra, a Belgian Malinois, is a super sniffer, able to sniff out COVID with 99 per cent accuracy.
She and her partner, One Betta, a Dutch Shepherd, work a checkpoint together at Miami International airport. They are part of a pilot program with the Global Forensic and Justice Center at Florida International University that uses detection dogs as a quick screen to identify people with COVID-19. Their detection rate is high – at more than 98 per cent – and the program has been such a success that it’s being extended for another month at the airport.
The dogs have been so accurate in their detection of COVID-19 that they and other canines with similar training could be deployed to other places that have many people coming and going at once, including other airports or even schools. COVIDsniffing dogs are being used in university classrooms now. Cobra is given passengers’ masks to sniff as the travelers make their way through a security check.
If she identifies a specific scent, she’ll let her handler know by sitting down. Sitting means Cobra has detected an olfactory signal of the coronavirus. That means the passenger will get a swab. Cobra and One Betta got their start learning to identify the presence of laurel wilt, a fungus that attacks avocado trees and kills them, costing Florida growers millions of dollars.
Once a dog learns to identify one odour, it is easily trained to identify other scents assigned to them. Cobra and One Betta were trained using mask samples from people hospitalized with COVID, and a control group of people who did not have the disease. When the dog correctly identified the virus, it got a favorite toy. From Aug. 23 to Sept. 8, the two canines screened 1,093 people during eight working days, alerting on only one case.
That person had tested positive for COVID two weeks earlier and was returning to work after quarantine. While the follow-up rapid test was negative, it highlights the exquisite sensitivity of the sniffers.