The title of the world's "oldest ever dog," Bobi, who passed away in October at the reported age of 31, is under investigation by Guinness World Records (GWR), prompting a provisional pause on both the titles for the oldest living dog and the oldest dog ever, as disclosed by a GWR spokesperson to CNN on Tuesday.

The age verification for Bobi had initially been confirmed by the Veterinary Medical Service of the Municipality of Leiria, stating he was registered in 1992, a claim also verified by the Portuguese government-authorized pet database, SIAC, according to GWR's February announcement. Bobi allegedly lived for 31 years and 165 days until his demise in October.

However, doubts arose after Bobi's death, challenging the evidence supporting his reported age. GWR, in response, initiated a formal review, a process triggered when a record title is contested. This comprehensive examination involves scrutinizing existing evidence, seeking new evidence, and consulting experts and those associated with the original application.

Bobi's owner, Leonel Costa, claimed that the dog's remarkable longevity was attributed to factors such as roaming freely without a leash, residing in a tranquil environment, and consuming human food soaked in water to eliminate seasonings. Bobi, a purebred Rafeiro do Alentejo, a livestock guardian dog breed, exceeded the typical life expectancy of 12-14 years, according to the American Kennel Club.

Bobi spent his entire life in Conqueiros, a small Portuguese village, frequently seen mingling with cats. The previous record holder for the oldest living dog and the oldest dog ever was Australian cattle-dog Bluey, born in 1910, who lived to the age of 29 years and five months.