WHEN Karen Woolley borrowed a metal detector from her auntie, she didn't expect to be using it on her puppy.

But after her diamond ring went missing there was only one possible suspect – four-month old cockapoo Barney.

Barney had to have an hour-long operation to remove the ring, and now Ruddington Veterinary Centre, which treated him, is warning puppy owners to keep their pets away from small objects.

Mrs Woolley, 40, had taken her rings off to have a bath and left them on her bedside cabinet.

"When I went to put them on again the next morning, I realised that the diamond ring had disappeared," she said.

"My husband Jonathan and I were searching everywhere, and then he had the idea of using the metal detector.

"We put Barney on the floor and ran the metal detector over him and he started to bleep."

The ring that Barney had swallowed had been given to Mrs Woolley by her grandmother.

"It was her engagement ring," said Mrs Woolley, who is setting up a bed-and-breakfast at her home in Thrumpton. "She's 104 in two weeks' time. It's gold and has three big diamonds, so it is probably worth a lot, but it's also very precious sentimentally."

As Barney, a cross between a cocker spaniel and a miniature poodle, is so small, the ring could not pass through him naturally.

In an hour-long operation last Thursday, Barney was put under anaesthetic and his stomach cut open so the ring could be removed.

Mrs Woolley said: "Barney is usually a very bouncy, happy dog, and we normally take him for walks twice a day.

"We've not been able to walk him since the operation, so he's getting very frustrated.

"My two-year old daughter Issabelle loves Barney and all she wants to do is play with him, but I've had to keep them apart.

"It's horrible seeing him in pain and it's been a very upsetting, and expensive, experience."

Mrs Woolley has begun to wear the ring again and makes sure she puts it into a box in a drawer if she takes it off.

Jane McLachlan, practice director at Ruddington Veterinary Centre, said they often see puppies after swallowing small objects, especially toys.

She said: "It's unusual for an object to be removed in an operation, as it usually passes through naturally, or by using liquid paraffin to lubricate the stomach.

"As the ring was so large, and the diamonds stuck out, it could have done a lot of damage if we didn't remove it. Puppies can be very curious and we'd advise owners not to let them play on their own and to keep small objects out of reach."