It is horrible.
last month i had two attacks on my lambing flock.
one in lamb ewe, half her face ripped, one in lamb ewe chased through a fence, badly cut legs, one in lamb ewe dead and others with bite marks on their legs.
result? vets bill, the dog shot dead by a neighbour whose ewes were also attacked. Police involved, statements given, owner identified.
I had to be very firm with the police about charging the owner (local) apparently even though it is an offence for any dog to be at large, the owner did not have any previous criminal convictions so the CPS guidelines are that they should not be charged and taken to court