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 12 to 14 years -- was also declared the oldest dog ever, breaking a nearly century-old record held by an Australian cattle dog named 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 spokesman told AFP.
The reference site for extreme achievements did not say what had raised their suspicions.
But skeptics cited by British and US 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 Miguel Figuereido, a veterinarian in Lisbon, 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's owner, Leonel Costa, insisted that all the "suspicions are unfounded".
In a statement sent to AFP, he said that the certification procedure "took almost a year" and that he had complied with all the requirements demanded by Guinness.
Costa accused "a certain elite in the veterinary world" of being behind these suspicions, because they had difficulty accepting that Bobi had always fed on a "natural diet" instead of dog food.
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 woodshed 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.
They unwittingly left one puppy -- Bobi -- behind and were eventually persuaded by Leonel Costa and his sister to keep him.
Costa has 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 and spent his days lolling around the yard with the family cats, he said.