Research has revealed that dogs possess the ability to detect Covid-19 infections more rapidly, with greater precision, and at a lower cost than even the most advanced current technological methods available.
This capability stems from their intricately developed olfactory faculties, enriched by both physical and neural optimizations for scent perception. Dogs possess a multitude of olfactory receptors, numbering in the hundreds of millions, in stark contrast to the approximate five to six million receptors present in humans. Additionally, dogs dedicate a significant portion of their brain, around a third, to the interpretation of scents, while humans allocate only about 5 per cent.
These enhancements equip dogs to identify exceedingly minute concentrations of odours associated with Covid infections. Over the past couple of years, a growing body of research has showcased the proficiency of dogs in detecting the elusive virus and its various strains, even when obscured by other viruses such as those responsible for the common cold and influenza.
Studies indicate variety of other dog breeds are also up to the task
Tommy Dickey, a Distinguished Professor Emeritus at the University of California-Santa Barbara, and his collaborator Heather Junqueira of BioScent Inc., consolidated these numerous recent findings into a comprehensive review published in the Journal of Osteopathic Medicine. Their assessment asserts that collectively, the research demonstrates that trained scent dogs are often “as effective and sometimes more effective” than both the antigen tests used at home and the gold-standard reverse transcription polymerase chain reaction (RT-PCR) tests employed in medical settings.
The proficiency of dogs extends beyond their faster detection of the SARS-CoV-2 virus. Notably, they accomplish this detection without invasive procedures and without contributing to environmental concerns associated with single-use plastics. Their olfactory capabilities are exemplified by their capacity to identify the equivalent of a single drop of an odorous substance within 10.5 Olympic-sized swimming pools. This level of sensitivity is approximately three orders of magnitude better than scientific instruments can achieve.
In certain instances, dogs have successfully detected Covid in individuals who were pre-symptomatic or asymptomatic, cases where conventional tests were ineffective due to low viral loads. Furthermore, dogs have demonstrated their ability to differentiate between Covid and its variants, even when confronted with other potentially complicating respiratory viruses such as those causing the common cold or flu.
Beagles, basset hounds, and coonhounds, known for their natural inclination to engage with the world through odours, are considered ideal candidates for scent detection. Nevertheless, the studies indicate that a variety of other dog breeds are also up to the task.
Despite the mounting evidence, this remarkable ability of dogs is still sometimes perceived as a curiosity, according to Dickey.