We knew the detection dogs of drugs, bombs, but also cancer or even Parkinson’s disease. Here is again in the center of our attention the extraordinary acuity of smell dogs and that could well be used to detect Covid-19 in humans. Hope, at a time when laboratories are saturated with requests for PCR tests. Let’s do a check in.
Covid-19 sniffer dogs: very promising results
Sniffer dogs have been trained to recognize different metabolic substances as well as volatile organic compounds produced by the body of people with Covid. This set of substances that we call volatiloma gives off a specific odor that dogs are able to detect after about 20 days of training.
Various scientific experiments have of course been carried out in many countries: in Germany, the Arab Emirates, Russia, Lebanon or even Chile, Great Britain, Finland and France. All of them showed the high reliability of results. Sniffer dogs were also able to identify ” pre-symptomatic cases »Yet revealed negative by RT-PCR tests carried out in the laboratory. In other words, even before the appearance of specific symptoms, people have been identified positive by means of smell detection.
These various analytical studies have made it possible to obtain extremely promising results. For example, the one carried out in France as part of the “NOSAÏS Project – Covid-19” – a project supported by the World Health Organization (WHO) and initiated by Professor Dominique Grandjean, teacher-researcher at the National Veterinary School d’Alfort (EnVA) – highlights a sensitivity of more than 95% to certain specificities, the study covering nearly 370 tests carried out with only 8 dogs and it is also noted that 50% of these animals have demonstrated efficacy of 100%. In Germany, a study carried out on 10,388 samples sniffed by 7 dogs, shows sensitivity rates of 82.6 and 96.3%.
In Finland, dogs detected the virus after sniffing wipes that had previously been passed on the skin of volunteers at Helsinki-Vantaa airport. These passengers were also subjected to a laboratory test. In both cases, the results were identical, but those obtained thanks to the impressive flair of the canines turned out to be faster.
Who are these Covid-19 detector dogs?
In Chile, the Police are collaborating with a Labrador and three Golden retriever previously used to search for missing persons or explosives. In France, and more precisely at the veterinary school of Alfort, it is with samples of human sweat that six dogs are trained to detect SARS-CoV-2 in Accommodation Establishments for the Dependent Elderly ( Ehpad): one of them is the dog of the Veterinary School of Alfort and the others are fire fighting dogs.
But at the national level, in nursing homes and other health structures there are more than 300 assistance dogs and we have already trained a number of them in the detection of Covid patients. The Handi’Chiens association is also strongly involved in this action.
Covid-19 Sniffer Dogs: Why Does It Work?
We now know that these animals have a amazing ability to detect the disease and that they can be operational in a minimum of time, both in the field of the detection of Covid-19 patients and in that of prevention at the level of human health.
The virus itself does not emanate an odor, but the metabolism undergoes changes due to the infection. For example, the perspiration of a patient undergoes variations that a dog can smell. But it can also be sensitive to small changes in body temperature. This is the reason why trained dogs could be used at airports, train stations and other places of passage.
If we have more and more often recourse to the impressive flair of canines, it is because the screening is less invasive than PCR tests, but also because the lead times for obtaining results are shortened and the said results are of a high reliability. If this practice were to become more widespread, biology laboratories could then see the burden weighing on them decrease. The mass screening strategy could thus be carried out smoothly …
With such impressive flair, a dog only needsa tenth of a second to spot a specific smell. It is therefore not surprising that the Academy of Medicine strongly encourages the use of sniffer dogs to detect Covid-19 patients. And let us be reassured, our four-legged friends are not very inclined to be themselves contaminated by this Coronavirus.