Dogs can be trained to detect Heterobasidion root rot in the forest

Heterobasidion root rot caused by Heterobasidion parviporum is the most destructive disease affecting Norway spruce, while H. annosum s.s. is the primary causal agent of root rot in Scots pine. Early diagnosis of these pathogens is essential for effective disease management. Dogs, with their highly developed sense of smell, may have significant potential to detect forest pathogens before they cause severe damage. In this study, we evaluated whether trained volunteer dog-handler teams could identify Heterobasidion spp. from wood, fruit bodies, or mycelia in vitro and in vivo, aiming to enhance early detection of Heterobasidion root rot in pine and spruce forests. Dogs were successful both in young and mature pine stands to detect trees infected by H. annosum s.s. Seven dogs indicated H. annosum s.s. with a mean sensitivity of 72% and mean precision of 84% in young pines. Three dogs indicated infection with a mean sensitivity of 88% (precision 99%) in mature pines. Five of nine dogs achieved sensitivity over 70% in indoors scent discrimination line-up test. The results indicate that dogs can be used as an aid in searching for Heterobasidion spp. in Scots pine and Norway spruce stands, but further testing is needed in larger areas.