Mizzy the massive mastiff takes on rotund rabbit and corpulent cat for diet challenge

Five-year-old dog weighs more than the average UK woman

An 11-stone bullmastiff dog has become the fattest pet to enter an animal charity's fit club.

Mizzy tips the scales at 11 stone 4lb (72kg), weighing more than the average UK woman.

The five-year-old needs to lose more than a third of her body weight to reach her ideal size, according to PDSA which runs an annual Pet Fit Club.

The dog, from Littleover in Derby, is so large that her collar fits around the waist of the charity's veterinary nurse who is now in charge of her strict diet.

Mizzy is one of 21 overweight animal finalists - including a two-stone Norwegian Forest cat and an 11lb rotund rabbit - taking part in a six-month diet and exercise programme.

Owner Cheryl Pedley described Mizzy as a "giant cuddly teddy bear".

The 50-year-old said: "We got Mizzy when she was a year old and she has always been a big girl, but wasn't overweight.

"Then in early 2011 she had pyometra (a potentially fatal womb infection) and had emergency surgery. This and some other health problems severely restricted her mobility and she just piled on the pounds in just six months.

"She isn't given any naughty treats at all, just dental sticks."

Veterinary nurse Sue Bartlett, who is monitoring Mizzy at Derby's PDSA PetAid hospital, said: "Mizzy is morbidly obese, which can have very serious consequences on her health and life expectancy.

"Overweight pets are less mobile, less willing to play and more likely to develop a number of serious health conditions.

"The good news is it's never too late to make a positive change and improve a pet's lifestyle. We're confident that Mizzy will have a slim-line figure and new lease of life by the end of the competition."

Ms Pedley added: "I knew she had gained weight but simply didn't realise how overweight she had become, I knew her breed was supposed to be big.

"She used to love long walks so I didn't think anything of giving her big helpings then, but I should have adjusted her food when her activity levels decreased - hindsight is a wonderful thing.

"When the vet explained the problems her extra weight was causing her I wanted to do everything I can to help her. I couldn't bear to lose such an adorable dog to something preventable, so I entered her into PDSA's Pet Fit Club."

Mizzy and the other finalists will compete for the title of PDSA Pet Fit Club slimmer of the year.

PA