Dog owners in Sheffield are being urged to keep their pets on leads to avoid attacks on livestock.
The warning came after a pregnant ewe in Dore was put down after an attack.
Police said the dog owner was spoken to by the farmer and the incident has been resolved, but local farmers want to avoid any further attacks,
PC Matt Duffy said: “The lambing season will soon be upon us, so there are still pregnant ewes on the moors.
“I’d remind dog walkers keep their dogs on leads in areas where it is possible that there might be sheep or other livestock.
“Any dog can act on its natural instincts and chase a sheep, which may appear to be out of play or aggression, but can result in the sheep aborting a lamb or causing itself injury as it flees.”