Jack, who has arthritis and a bad back, still has the energy of a puppy
Owners Ray and Mary Bunn say their pooch is a big part of the family
Oldest dog alive thought to be a 26-year-old Jack Russell, called Meg
If confirmed Jack would be eighth on Guiness World Records all-time list
Like most when they reach over 100, Jack the Yorkshire terrier has got a bad back and his legs do not work like they used to - but surprisingly he still gets mistaken for a young pup.
Jack may not be able to go on the same long walks he once enjoyed, but at 177 dog years and 25 human years, he is as happy as he was in his pomp.
Now believed to be Britain's oldest dog, the terrier was rescued by Ray and Mary Bunn 16 years ago, from a couple who could no longer care for him.
Nation's number one: It is believed that Jack the Yorkshire terrier, pictured, is Britain's oldest dog
Mr Bunn, of Hartlepool, County Durham, said they had an 'instant bond' with little Jack.
He said: 'My daughter's next door neighbour spotted a couple who were going to tie him to a tree and leave him there. She took him in, but their dog didn't like him.
Good for his age: Jack, pictured, is often mistaken for an energetic puppy despite being 117 in dog years
'My daughter told me about it and asked me to go round and the first time I saw him, he came running over to me and jumped into my arms.
雷第一次與傑克見面時,傑克就撲到了他的懷中,這讓他感覺很有趣。
Keeping an eye: Jack, pictured, watching Mrs Bunn eat, was adopted by his owners when he was 10
'I didn't even hold my arms out - the bond was instant. He very quickly became a big part of the family, and now we've had him for 16 years.'
它熱愛美食,像年輕的狗狗一樣充滿活力。
Energetic: Jack, pictured, does not have as much strength in his legs but still has the energy of a young dog
因為患有關節炎,它無法長時間跑動。
One from the album: Pictured, an old family photo shows Jack staring intently at someone's plate of chips
According to the record books, Jack could be one of the oldest dogs ever to have lived, and would be eighth on an all-time list if his age was proven by Guinness World Records.
The oldest dog in Britain was 25-year-old Jack Russell Meg from Somerset, who died last year.
However, if the pensioner pooch wants to take the global crown he has to wait another three years.
The oldest dog ever to have lived was an Australian cattle dog named Bluey, who reached 29 years and five months before being put to sleep in 1939.
Mr Bunn said: 'Someone the other day thought he was a puppy, but he has arthritis and can only walk so far.
'He's on tablets, but he's all right, and eats and drinks fine. He's having some problems with his back and his legs as he is getting older, but he's fine.
'Jack has always been a very friendly dog, but he hadn't been looked after properly before he came to us.
'He had a brother, and we heard that he had been fed to a rottweiler, so he was facing a horrible future before my daughter's friend took him.
'He has always felt at home here. He's generally a very happy dog and we all love him.'