Can dogs detect COVID-19 better than a PCR test?

Many scientists are currently using sniffer dogs to rapidly detect and identify people infected with COVID-19. By grouping several studies on the subject, researchers explain that this is a particularly promising lead, and that it could even be as effective, if not more so, than PCR and antigenic tests.

It's already been established that dogs, considered genuine noses on paws, are able to detect a wide range of molecules in extremely low concentrations, much more so than humans.

An extraordinary ability that is already being used to research and identify diseases such as cancer, diabetes, malaria, or Parkinson's disease.

Since the beginning of the pandemic, many organizations, associations, and researchers have been working together in several countries to train dogs to detect the novel virus. This has been particularly the case in the United Kingdom and France, with the goal of benefiting from more rapid and non-invasive screening that would make it possible to detect the disease in places frequented by thousands of people. Last August, the French National Academy of Medicine and the Veterinary Academy of France themselves encouraged these tests and called for "further scientific evaluation."

And now this is the subject of a new report recently published in the Journal of Osteopathic Medicine, in which researchers are investigating the feasibility and effectiveness of using these dogs to screen for covid-19. The scientists have gathered several studies on the subject, which "demonstrated that the sensitivity, specificity, and overall success rates reported by the summarized scent detection studies are comparable to or better than the standard RT-PCR and antigen testing procedures."

Encouraging results that could make it possible to use these dogs to detect disease in hospitals, senior care facilities, schools, universities, airports and large public gatherings.

"Accurate and rapid screening of individuals who may be carriers, symptomatic or asymptomatic, of the COVID-19 virus will remain important for slowing and limiting the spread of infection.

These preliminary studies suggest the use of medical scent detection dogs offers a promising approach," said Tommy Dickey, PhD, professor, University of California, Santa Barbara.

Up to 100% success rate

Researchers focused on four recent studies focusing on the detection of covid-19 by sniffer dogs. The first one, based on the work of French and Lebanese researchers, showed that after only four days of training, the success rate of the dogs varied between 83% and 100%.

In the latter case, the dog had been trained to sit only in front of covid-19 positive samples.

In another study conducted by German researchers, dogs were trained for one week to detect the virus in samples of saliva or tracheobronchial secretions taken from infected patients. In this case, the overall average detection rate was 94%.

Interestingly, research conducted by a scientific team in Colombia even showed that dogs were able to detect the virus in asymptomatic or pre-symptomatic individuals.

"Of the 6,000 samples, the dogs' performances [in that study] resulted in a sensitivity of 95.5% and a selectivity of 99.6%," Dickey commented.

Despite these results, the researchers remain cautious and believe that "there remain challenges to be considered before broad-scale implementation of scent detecting dogs to identify and screen for covid-19.

That said, this has not prevented them from encouraging this avenue for pilot studies at airports or sporting events.