Twenty armed police and a helicopter were called out when two bull mastiffs savaged a flock of sheep.
Officers in flak jackets surrounded a field during the £10,000 attack, described as like a horror movie.
Farmer Tom Hadley fired his shotgun and the dogs fled.
They killed 31 lambs and 14 had to be put down.
Mr Hadley, of Leominster, Herefordshire, said: It was absolute carnage. There was blood everywhere.
A 64-year-old man has been arrested. The dogs are now in a police pound.
News Source MirrorNews