Alan Wilson, 59, witnessed the attack at Manor House Farm on German Lane, Charnock Richard, and now wants to see the owner of the Staffordshire Terrier caught and prosecuted.

Mr Wilson was out on a field when he saw the terrier tear into two six-month-old lambs.

One of the animals received an injury to its eye and the second one received injuries to its mouth and legs during the attack

His wife Linda, 53, said: "The vet came out to examine both lambs – one of them is on the road to recovery but the other one is still poorly and it's possible that it could die because it was a huge shock to its system.

"We have got an idea of who the owners are because we have seen them walk their dogs here before.

"The owner of the dog actually stood there and saw the attack and did nothing to stop the dog.

"They didn't have the dog on a lead and it just ran on to the field, which we had fenced off recently – we don't have any idea how the dog managed to get into the field."

She added: "By law, my husband would have had the right to shoot the dog for attacking our animals, but he didn't have a gun.

"We called the police and they made door-to-door inquiries with the neighbours – they've been very helpful."

The couple have also been in contact with Chorley Council's dog warden.
They have kept livestock at Manor House Farm for the past six years.

Two women in their 30s, one of them believed to be the owner, were spotted at the scene and police are trying to find them.

A spokesman for Lancashire Constabulary said: "We received a call at 1.22pm on Thursday that animals had been attacked on a field at Manor House Farm.

"The dog ran off towards the railway bridge and we are making efforts to track down the owner."

Anyone with information should phone Crimestoppers on 0800 555111.