Members of the public are being urged to keep their dogs under control in the countryside in and around Rivington, after a series of vicious canine attacks which have seen around 25 sheep killed over the past five weeks.
Water company United Utilities owns and maintains the spectacular countryside estate, and has several tenant farmers whose sheep have fallen prey to free-roaming dogs.
In each case, the sheep were left so badly injured that they had to be put down by farmers.
The company has now put up extra signs warning people to keep their dogs leashed, and is calling on owners to act responsibly.
Farmer John Needham, from Higher Knoll farm, has lost more than twenty sheep since mid-December, costing him thousands of pounds and a great deal of distress.
He said: "There seem to be more and more people coming into Rivington to exercise their dogs, which is obviously fine, as long as they obey the rules.
"I've lost twenty one sheep in the past few weeks. It has been difficult from a financial point of view, but worse than that is seeing the suffering of the animals, which is very distressing.
"United Utilities is doing what it can, but the owners themselves must take responsibility."
Hazel Gannaway, one of three countryside rangers from United Utilities working at Rivington said: "The sheer number of attacks since December has been unprecedented.
"When a sheep gets killed, it can be extremely traumatic for the animals involved, the farmer and the dog owner - who is often taken completely by surprise by their pet's behaviour.
"We are calling on all owners to act sensibly. Extra signs have been put up around the estate, and we will be reporting all offenders to the local police If you are coming to Rivington, please, please, obey the law, and keep your dog under control."
PC 3024 Matt Lee, Adlington Community Beat Manager at Lancashire Police, added: "Over recent months there has been a significant increase in cases of dogs worrying/attacking Livestock in the Rivington and Anglezarke area.
"As a result of this the Adlington Neighbourhood Policing Team are planning to work in conjunction with United Utilities, Chorley Council Neighbourhood Officers and Greater Manchester Police to overcome this issue.
“We will be increasing patrols throughout the area and will seek to take positive action against anyone not taking steps to keep their dogs under control."