Phillip Uren shot the two dogs with his rifle and strung one of them up on a sign out the front of his property to set an example and warn all pig dog owners that their dogs will face the same fate if they enter his land.

He hung a sign of the dog reading: "If this is your dog I want to see you and bring your cheque book."

"I have had a gut full. There is wool all over my paddock where the dogs ran loose and bit chunks out of them," he said.

"It's not just the sheep I lose, but the lamb and the wool. This is my livelihood.

"You speak to any pig dog owner and they say their dog won’t kill sheep, but they do."

Mr Uren found the dogs on Sunday morning. As he chased one, trying shoot it, the dog turned and tried to attack him.

"This isn’t the first time and it won’t be the last," Mr Uren said. "Every now and then this happens but I have no hesitation in shooting them. I have a right to protect my land.

"I have lost up to 70 in one night before."

At least two sheep were killed after the dogs mauled their necks.

Other sheep have bite marks where the dogs bit chunks out of them. Mr Uren said he would not know how many had been bitten until they were shorn.

"Anyone with complaints can come and talk to me, I have no hesitation showing them what these dogs have done," he warned.

An RSPCA spokesman said Mr Uren had every right to shoot the dogs and protect his property.

"If you have an animal that is aggressive it is your responsibility to make sure it is restrained," he said.

"However, unless we were to find the owner then we don’t have a case."

Collie Police Senior Sergeant Rod Boehm said dog owners should take more responsibility for their dogs.

"If you take a dog out hunting and don’t bring it back, then take precautions to warn farmers," he said.

Collie Shire ranger Tony Heppener said if the owner was found the shire could prosecute.