A Jack Russell has undergone rare gender assignment surgery in Glasgow after she was born with both male and female parts.

Little Molly's owners, Mary and Frank Finlay, took the puppy to their local vet after they become concerned about her behaviour.

Veterinary surgeon Ross Allan said it is the first time in his 15-year career that he has come across a case like Molly's.

"I'll be honest, in terms of her condition it is extremely rare," says Ross.

"She is certainly unique to me. She was four months old when Mary and Frank first brought her in after they noticed her displaying quite masculine behaviour."

Molly had been rubbing herself against furniture, causing discomfort and abrasions to her skin.

On closer examination, Ross discovered the little dog's anatomy was quite unusual.

Ross said: "Molly was what is defined medically as a male pseudo hermaphrodite or more commonly 'intersex'.

"Her particular anatomy meant that whilst Molly appeared to be a female, closer examination revealed elements of both male and female external genitalia and unfortunately this was leading to significant genital discomfort."

The award-winning vet said he thought extremely carefully over what would be in Molly's best interests before he decided to go ahead with the gender reassignment surgery.

"It had to be what was best for the animal's welfare," he said. "In this case, it meant performing a procedure that would give her the best quality of life."

To give an idea of how rare this type of surgery is, science website Pubmed, which comprises more than 26 million citations for biomedical literature, only has 13 academic entries on gender reassignment in dogs.

"It definitely is very challenging surgery," said Ross.

"We waited until she was six months old to perform it, to give her a better chance of recovery."

The vet, who passionately describes his work as a vocation rather than just a job, said he "loves animals" and the science and learning that goes with his career.

As Molly underwent surgery, he found the dog had male internal sexual organs as she had testicles in place of ovaries within her abdomen.

If left untreated, it could have risked her developing a long-term and debilitating condition.

The surgery, which took place a year ago, was a success and Molly has now made a complete recovery to the delight of her owners.

"She's a wonderful wee dog and we love her to bits," said Mary.

"Frank is retired and I am at home recovering from a heart attack so she means a lot to both of us. She has flown through this and loves her chicken and her sausages for her supper.

"She can be a bit naughty though and likes to hide our slippers - it took two months to find Frank's pair as she'd hid them behind a unit."

Molly has doubled in weight since her surgery and vet Ross says he's delighted with her progress.

"Intersexism is rare, and some cases will not require any treatment at all," said Ross

"In Molly's case it was a painful condition which was causing problems and surgery was an important step to ensure she is able to go on to live a pain-free life."