From a distance she looks like any other dog chasing a ball in the park - but a closer look reveals she is the victim of a genetic mutation caused by irresponsible canine breeding.

Zebedee, a four-year-old white miniature bull terrier, had to have her eyes removed after suffering from primary lens luxation (PLL), a painful condition which causes the eye to break down.

PLL develops because of a genetic mutation in several breeds of dog and now the right side of her face is also beginning to collapse.

Neither of these disorders were disclosed when Zebedee was sold as a puppy and her case has led for campaigners to call for greater regulation of how certain dog types are bred and sold.

Lynne Hughes and Tino Oxinos, who lives in South Park Road, Wimbledon, have also appealed for vets to give Zebedee a free MRI scan (worth about £1,000) to see why the muscles in her face are now beginning to atrophy.

Ms Hughes said: “We were told she only had weeks to live, so just to still have her around is great, but we want to know why her face is caving in and what can be done to stop it.

“She‘s such a loving dog and she still loves to run around and chase after balls if she can hear them.

"She obviously has to be walked in a specially made pram just to be on the safe side.

“I hope somebody can help us have this MRI scan so we can know for sure what is wrong with Zebedee.”

The collapse in Zebedee’s facial muscles is believed to be because of another genetic disorder, myosotis gravis.

Juliet Shaw, a breed health co-ordinator for miniature bull terriers for canine welfare group, the Kennel Club, warned when buying puppies they should check with the breeder what DNA tests have been made to screen for disorders.

She said: “Some breeders are just in it for money and don’t care what happens to these poor dogs. It’s very sad and needs to be regulated.

“Every breeder who breeds more than five litters a year must have a council provided breeding licence, but there are fears over whether the council has the resources to police this properly.

“Personally I think anyone who breeds a dog should have a licence, even if they only produce two a year.”

She added that, if myosotis gravis is the cause for the dog's recent decline in health, Zebedee can be kept alive with a course of steroids.