Sniffer dogs show promise at detecting COVID-19

Scientists at the University of Veterinary Medicine Hanover have found that trained sniffer dogs could be used to detect COVID-19 in human samples with a relatively high rate of accuracy, a study published on Thursday revealed.

Eight sniffer dogs from the German Bundeswehr were trained for only a weekto distinguish between the mucus and saliva of patients infected with coronavirus and non-infected individuals.

The dogs were then presented with positive and negative samples on a random basis by a machine.

'Potential to take this further'

The animals were able to positively detect SARS-CoV-2 infected secretions with an 83% success rate, and control secretions at a rate of 96%. The overall detection rate, combining both, was 94%.

In its conclusion based on more than 1,000 sniffed samples, published in the BMC Infectious Diseases journal, the team said dogs could play a role in detecting infected individuals.

Sniffer dogs that normally look for explosives or drugs have been used previously to smell various cancers and hypoglycemia in diabetics. This medical application motivated veterinary scientists to research the potential ability of sniffer dogs to detect the coronavirus. 

"We think that this works because the metabolic processes in the body of a diseased patient are completely changed and we think that the dog is able to detect a specific smell of the metabolic changes that occur in those patients," said Professor Maren von Köckritz-Blickwede, a specialist in the biochemistry of infections.

Read more: Dogs can sniff out COVID-19

"What has to be crystal clear is that this is just a pilot study," said Holger Volk, chair of the university's department of small animal medicine. "There's a lot of potential to take this further — to really use these dogs in the field."

In their conclusion, the team envisaged using sniffer dogs to detect infectious individuals in certain places. 

"In countries with limited access to diagnostic tests, detection dogs could then have the potential to be used for mass detection of infected people," said the conclusion. "Further work is necessary to better understand the potential and limitation of using scent dogs for the detection of viral respiratory diseases."

Read more: COVID-19 half a year later: What have we learned?

The samples with which the sniffer dogs are being tested were chemically rendered harmless. The question remains whether the canines can detect active coronavirus cases in patients. 

The researchers are also looking at how well dogs can differentiate between samples from COVID-19 patients and those with other diseases such as flu.