High probability of pet dogs encountering the sylvatic cycle of Echinococcus multilocularis in a rural area in Hokkaido, Japan.

Surveillance of Echinococcus multilocularis in 98 pet dogs kept in a rural area of Hokkaido, Japan, from March 2018 to March 2019 suggested infection in seven dogs (7.1%) by E. multilocularis-specific copro-DNA examination, and one of them excreted E. multilocularis eggs that were identified by sequence analyses. Among the infected dogs, three were not allowed to run free when outdoors. Based on detection of E. multilocularis eggs in fox feces collected from roadsides in the same area, dogs kept in rural areas may have a high probability of becoming infected after preying on infected voles along such roadsides, even in domesticated settings. Therefore, examination along with periodic deworming administration is considered necessary to prevent transmission from dogs to owners.