K9 Covid Sniffers Show Promise
Follow up from February 2021 Report
A new study published in Mid-May indicates dogs might be able to lend a helping paw in the fight against Covid-19.
Scientists have completed Phase 1 of a trial examining whether, under controlled conditions, dogs might be able to smell and identify Covid-19 infection. In the Phase 1 trial, working dogs were tasked with detecting Covid-19 on samples of clothing and masks. Researchers examined whether the dogs could distinguish between samples positive and negative for Covid-19.
Six dogs participated in the study, ranging in ages from four to six years old. The group – (In Photo Above) included Labrador, Golden Retriever and Cocker Spaniel breeds. Researchers said the dogs were able to pick up the scent of Covid-19 after six to eight weeks of training.
The researchers place a series of sweaty T-shirts and distractors—clean clothing, shipping materials, or rubbing alcohol—all inside mesh-covered cannisters on the ends of an eight-spoke metal wheel. Only one cannister will contain a T-shirt worn by a person who tested positive for COVID-19 within 48 hours of wearing it. The dogs know to walk around the wheel until they detect that positive sample.
In the April study with urine and saliva samples, dogs could find the virus with 96 percent accuracy, Otto says. While the current study using sweaty T-shirts is ongoing, the canines have been remarkably successful at that too, she says.
Roxie is their fastest dog: She’s walked the wheel and found the positive sample in as little as 12 seconds. Rico, a more pensive pup, takes about 23 seconds to identify the right shirt.
“The results are extremely exciting,” said James Logan, a project lead on the study.
The dogs showed a sensitivity rate of around 82%-94% in detecting Covid-19. Chemical analysis of the infection showed a “distinct” odor associated with Covid-19. Researchers are in the process of identifying the exact chemicals behind this odor. The specificity rate, which measured the ability of the dogs to indicate whether someone did not have Covid-19, ranged from around 76% to 92%.
“Dogs could detect Covid with incredible speed and accuracy,” Logan said — “even if a person was asymptomatic.”
Study authors say a PCR test is still the “gold standard” for detecting Covid-19, but suggest dogs could provide a quicker and easier way to screen for Covid-19 in high-volume traffic areas. The dogs could also dissuade people from going to high-contact spaces while infected.
“The other thing about dogs is that they would serve as a visual deterrent, so if people knew that dogs were going to be screening at the airport, it’s very likely that people would think twice about traveling if they were infected,” Logan said.
A word of caution:
“This could be compromised by the density of individuals in crowded spaces and whether well-ventilated external spaces, where odours are rapidly dispersed, compromise the ability of the dogs to detect individuals with low levels of infection,” Lawrence Young, a virologist at Warwick Medical School who did not contribute to the study, said in a statement.
Phase 2 of this study will involve testing the dogs’ detection abilities on people actually infected with Covid-19, not just samples of clothing.