Dogs are better than conventional tests at detecting Covid-19

A scientific review has shown just how good dogs are at sniffing out diseases.

Their highly evolved noses, with physical and neural optimisations for smell, mean that dogs are able to detect Covid-19 faster and more accurately than antigen tests used at home, as well as reverse transcription polymerase chain reaction (RT-PCR) tests available in clinics and hospitals.

Researchers at the University of California – Santa Barbara assessed 29 peer-reviewed studies which together included more than 400 scientists from over 30 countries and 31,000 samples. The collective research demonstrates that trained scent dogs are “as effective and often more effective” compared to conventional testing.

“They can detect the equivalent of one drop of an odorous substance in 10.5 Olympic-sized swimming pools,” said UC Santa Barbara Distinguished Professor Emeritus Tommy Dickey, co-author of the review. “For perspective, this is about three orders of magnitude better than with scientific instrumentation.”

In some cases, dogs were able to detect Covid-19 in pre-symptomatic and asymptomatic patients whose viral load was too low for conventional tests to work. What’s more, dogs can distinguish Covid and its variants in the presence of other potentially confounding respiratory viruses, such as those of the common cold or flu.

Scent dogs such as beagles, basset hounds and coonhounds are ideal for detecting Covid-19. However, with a few weeks of training, puppies and older dogs, males and females, purebreds and mixed breeds all performed well.

We reported last year on previous research which found that dogs may be able to ‘see’ with their highly sensitive noses.