“I was in horror really,” she said. “You don’t really realise what you were looking at.”

Mary, who has 11 border collies, runs a sheepdog business from her smallholding. She condemned the people who mutilated her pet.

“I don’t think there’s any words to describe a person like that, not that you can print anyway,” she told the Herald.

Tarne went missing for around four days but when he returned, Mary didn’t realise straight away he had been butchered in that manner.

“He didn’t look like there was anything wrong with him, he just laid down in the straw next to me,” she said.

The dog was unusually quiet and it was not until she went to feed him in the evening that she noticed the wound.

But thanks to the vets, he’s on the mend.

“He’s on a heavy course of antibiotics, he’s virtually back to his normal self and back doing what border collies do, rounding things up.”

The vets got in touch with the RSPCA who are now investigating the offence and appealing for witnesses.

Inspector Adrian Langley said: “This is a specific offence in relation to mutilation and causing unnecessary suffering under the Animal Welfare Act.

“The police have been informed, because it is also a criminal offence relating to damaging somebody else’s property.”

Tarne went missing from Butlers Lane in Long Compton on Sunday 16th February and returned home four days later on Thursday 20th February.

Anybody with information should call the RSPCA on 0300 1234 999.