At 203 in doggie years, is Bella the mongrel the world's oldest dog ever?

But that's not bad going considering Bella the Labrador cross is around 29 years old.

That's 203 if every year of a dog's life equals seven human years.

The faithful pet is believed to be the world's oldest living dog and could even be the oldest dog ever.

Unfortunately her owner David Richardson, 76, has no documentation to prove her precise date of birth and so Bella's extraordinary longevity will never enter the record books.

Bella, the oldest dog in the world with owners David Richardson and Daisy Cooper

Mr Richardson bought Bella for £70 from an RSPCA rescue centre on June 21, 1982, when she was "about three years old".

They have been companions ever since.

But only this week the pensioner thought he was finally going to lose his faithful old friend.

Bella suddenly fell ill and was unable to walk.

With a heavy heart Mr Richardson made an appointment with the vet to put her down and dug a grave in her favourite spot in the garden of his home in Chesterfield, Derbyshire.

However, after a sleepless and tearful night Mr Richardson decided he couldn't go through with it.

He cancelled the vet's appointment and as if by magic Bella appeared as good as new as he filled in the grave.

Mr Richardson said: 'I phoned to cancel the vet because I just thought it would be better if Bella died in her sleep. She couldn't walk, but when I went out and filled in the grave she appeared behind me and was stood there watching. Since then she has been fine.

Bella is believed to be the world's oldest dog ever but there is no written documentation to prove her exact age

"I decided to take her to the vet to be checked and she said Bella was very fit for her age apart from a bit of arthritis in her legs. 

"Her heart is strong and she can still potter around the garden so she might have a good few years left."

The former soldier, deep sea fisherman and chef, said he originally wanted a German Shepherd but the RSPCA wouldn't allow it because he was 50 years old. 

"My choice was between Bella and another dog. She seemed friendlier so I chose Bella," he recalled.

In her youth, Bella was full of energy and enjoyed going on long daily walks with Mr Richardson. 

Now she quietly potters about the back garden when Mr Richardson or his partner Daisy Cooper, 81, are outside.

And with most of her teeth missing, she can no longer manage to gnaw on the remnants of a leg of lamb. 

"Bella has always had a good appetite and she only has the best. She has only got two teeth left so she can only have soft stuff now. So she has shredded chicken and fish.

"She will also have boiled liver and best tinned stewing steak, mackerel and sardines."

Bella still manages her favourite daily treat - sucking a toffee sweet while lying in her basket. 

Mr Richardson, who also owns a Border collie, has won a number of prizes at dog shows during their 26 years together.

Only last year at the Dronfield show, Bella competed in a team with three other "family" dogs and beat younger pedigrees to the top prize.

Mr Richardson said he had suspected for some time that she could be the oldest dog in England, but never dreamt she might take the world title.

The world's oldest ever official dog was an Australian cattle dog named Bluey. He was eventually put to sleep in 1939, aged 29 years and five months.

Until his death in 2003, the only other official Guinness World Records holder was Butch, a 28-year-old Beagle from Virginia, USA,  who held the title of "oldest living dog".

Gareth Deaves, records manager from Guinness World Records, said Bella would not be able to take over the titles held by Butch or Bluey "unless we can find some really clear evidence from the RSPCA" to prove her age.