Covid-19 and scent detection by dogs

The extremely sensitive olfactory sense of dogs, as a tool for detecting infections, is an ongoing research interest for DogRisk. The olfactory sense of dogs was tested during the covid pandemic in field at the Helsinki-Vantaa airport. The "corona dogs" were in duty at the airport providing airpassengers a change to get tested for corona infection.
Project background

In spring 2020, a joint agreement of cooperation on a research project was signed by the University of Helsinki, HUS, University of Eastern Finland, University of Oulu and NGO Wise Nose - The Smell Detection Association in Finland.

Research aimed first to investigate if trained dogs were able to identify and clearly point out positive samples of Covid-19 from urine and sweat (wiped from skin) samples. The aim of the study was to enable immediate and cost effective early diagnosis of the disease at a strategic site, the Helsinki-Vantaa International airport in Finland.

In addition, two yet to be published studies document how small concentrations trained dogs indicate successfully and how the dogs can be trained to work in smell detection, in order to create cost effective training programs for dogs in the future. 

The project was launched in autumn 2020 by docent Anna Hielm-Björkman and her Dogrisk-research group in cooperation with professor Anu Kantele from HUS, professor Olli Vapalahti from the University of Helsinki, the city of Vantaa, and Wise Nose ry.

The Covid-19 detection dog validation article is now accepted and will soon be published (14.3.2022).

Do you want to help the corona dog research? Make a donation to The Finnish Kennel Club’s corona dog research fund via our donations page. Choose "Other campaigns and funds", then "Veterinary Medicine" and then press the "Finnish Kennel Club Corona dog research" tab.

The Finnish Kennel Club launched a donation campaign in October 2020. You can also donate by bank transfer (Nordea: IBAN = FI15 1660 3001 0767 70, BIC = NDEAFIHH) by entering the following in the message field of the bank transfer: “The Finnish Kennel Club’s COVID-19 sniffer dog fundraiser” and your contact information. The following information should be added to the bank transfer instructions: “Recipient: University of Helsinki Funds”.

Covid-19 detection dog research by DogRisk

Please find our scent detection dog research with links to the full articles listed below.

Scent Detection Threshold of Trained Dogs to Eucalyptus Hydrolat (2024)

Dogs have an extraordinary sense of smell that is far superior to humans’, thanks to their unique anatomy and physiology. This remarkable ability allows them to detect and differentiate between very low concentrations of odor molecules, but the threshold seems to depend on the target odor. This study focused on determining the lowest concentration of Eucalyptus hydrolat that would be detectable by trained dogs. This substance was selected for the study as it is used in a dog scent training sport called “nose work”. The research involved testing dogs with progressively diluted concentrations of this hydrolat until they could no longer identify it, thus determining their scent detection threshold. When dogs were trained to respond to the Eucalyptus hydrolat at decreasing concentrations, they successfully detected the scent even when it was diluted to ratios between 1:1017 and 1:1021. The study also used analytical spectroscopy to analyze the contents of ten commercial Eucalyptus hydrolats, revealing variations in their ingredients. The findings highlight two key points. First, with appropriate training, dogs can learn to identify very low concentrations of Eucalyptus hydrolat. Second, the consistency of the scent source is crucial in training a dog, not only in canine sport competitions, but also in olfactory research.

Scent dogs in detection of COVID-19: triple-blinded randomised trial and operational real-life screening in airport setting

This large randomised controlled triple-blinded validation study with a precalculated sample size conducted at an international airport showed that trained scent dogs screen airport passenger samples with high accuracy. One of our findings highlights the importance of continuous retraining as new variants emerge. Using scent dogs may present a valuable approach for high-throughput, rapid screening of large numbers of people.

Expert considerations and consensus for using dogs to detect human SARS-CoV-2-infections
Research team

Team leader

Anna Hielm-Björkman

PI, Docent, ELT

University of Helsinki, DogRisk

Anu Kantele



Olli Vapalahti


University of Helsinki