The event held in Shimizu at the Tokachi Sen'nen no Mori (十勝千年の森) was canceled for this year and will be held
again next year. The course takes you on roads that run through forests and fields
used for dairy cattle. The race was canceled to prevent the spread of
hoof and mo...uth disease which doesn't infect humans, but which humans can spread "by carrying the germs on their clothes and body." (Wikipedia)
Here is a capture of the newspaper article announcing the cancellation.