Bobi the Dog's title as the world's oldest canine was suspended on Tuesday after the Guinness World Records began to doubt his actual age.
He died in October at the official age of 31 years and 165 days, eight months after the record-breakers' Hall of Fame declared on its website that he was the world's oldest living dog.
The purebred Rafeiro, a Portuguese race of livestock guard dog whose life expectancy is usually between 12 and 14, was also declared the oldest dog ever, breaking a nearly century-old record held by Australian cattle dog Bluey, who died in 1939 aged 29 years and five months.
"While our review is ongoing, we have decided to temporarily pause both the record titles for Oldest Dog Living and (Oldest Dog) Ever just until all of our findings are in place," a Guinness spokesperson told Agence France-Presse (AFP).
The reference site for extreme achievements did not say what had raised their suspicions.
But skeptics cited by British and U.S. media said Bobi's feet appeared to be a different color in photos of him as a puppy and snaps of him in his dotage.
And Lisbon vet Miguel Figuereido told AFP last year: "He doesn't look like a very old dog, with mobility problems or with an old dog's muscle mass."
Guinness World Records insisted the suspension was "temporary, while (the review) is ongoing."
Bobi, who was officially born on May 11, 1992, cheated death in his first days of life.
He and three other puppies were from a litter born in a wood shed owned by the Costa family in the village of Conqueiros in central Portugal.
Because the family already owned so many animals, the parents decided to get rid of the newborn puppies, recalled Bobi's owner, Leonel Costa, who was 8 then.
They unwittingly left one puppy, Bobi, behind and were eventually persuaded by Costa and his sister to keep him.
Costa attributed Bobi's longevity to the tranquility of country living and his varied diet.
He was never chained up or put on a lead and used to roam the woods around the village before he got too old to move much. He spent his days lolling around the yard with the family cats.