A musher rides his dog sled during a stage of the Sedivackuv Long dog sled race in Destne v Orlickych horach, Czech Republic, January 23, 2020. Dozens of mushers from around Europe are taking part in this year's 24th Sedivackuv Long Trail dog sled race, set in the Czech Republic's picturesque Orlicke mountains. REUTERS/David W Cerny

A musher rides his dog sled during a stage of the Sedivackuv Long dog sled race in Destne v Orlickych horach, Czech Republic, January 23, 2020. Beginning on Tuesday (January 21), 74 teams set out on the multi-stage race, simultaneously competing on two separate trails consisting of a 4-day 222km trail and 5-day 333km trail. REUTERS/David W Cerny

Dogs race during a stage of the Sedivackuv Long dog sled race in Destne v Orlickych horach, Czech Republic, January 23, 2020. The trails run through the mountainous forests of Northern Bohemia, close to the Polish border and pass along mountain ridges. REUTERS/David W Cerny

A musher rides his dog sled during a stage of the Sedivackuv Long dog sled race in Destne v Orlickych horach, Czech Republic, January 23, 2020. The race is called 'Sedivackuv long' in Czech, named after Kucera's dog 'Sedivak', who strayed just before the first race in 1997 and was shot dead by a local man. REUTERS/David W Cerny

Dogs race during a stage of the Sedivackuv Long dog sled race in Destne v Orlickych horach, Czech Republic, January 23, 2020. The race is the longest of its kind in the Czech Republic and reputed to be one of the most difficult in Europe. REUTERS/David W Cerny

A musher pets his dog before the Sedivackuv Long dog sled race in Destne v Orlickych horach, Czech Republic, January 23, 2020. REUTERS/David W Cerny