In the first half of this year wolves killed 138 sheep in the Netherlands, but the total for 2017 was less than 20, a wolf expert told the BBC.It is a new problem for the Dutch – March 2015 was the first time for 150 years that a wolf had been confirmed roaming in the Netherlands.Dogs kill far more sheep every year.Maurice La Haye, a biologist at the Dutch Mammal Society, said: “It’s very difficult to protect against a lone wolf – you can place electric fences round the sheep, but it’s expensive.”

Source: Rise in wolf attacks alarms Dutch sheep farmers – BBC News