The world’s oldest dog ever has been celebrating his birthday in Portugal.

Born on May 11th 1992, Bobi turned 31-years-old last week.

A big birthday party was planned on Saturday at his home in the rural village of Conqueiros, where Bobi has lived his entire life.

Bobi’s owner, Leonel Costa, said it was a "very traditional" Portuguese party.

Bobi is seen in 1999. Picture by: Guinness World Records

Local meats and fish were served up to guests, with extra for Bobi - who only eats human food.

Life has been hectic for Bobi since he was awarded his Guinness World Records title in February.

“We’ve had a lot of journalists and people come from all over the world to take a picture with Bobi,” Mr Costa said.

"They’ve come from all over Europe, as well as the USA and even Japan".

Mr Costa said Bobi has been in good health these past months, and was recently taken to the vet for a check-up.

He was concerned about potential physical and mental stress for Bobi after seeing so many visitors.

"There were a lot of pictures taken and he had to get up and down many times. It wasn’t easy for him," he said.

"His health was a little damaged, but now it's better".

Picture by: Guinness World Records

Bobi's birth date has been confirmed by the Veterinary Medical Service of the Municipality of Leiria, who registered him back in 1992.

Mr Costa has owned several old-aged dogs in the past, including Bobi's mother Gira, who lived to the age of 18.

However, he never thought any of his dogs would reach their 30s.

"If Bobi spoke only he could explain this," he said.

"We see situations like this as a normal result of the life that they have, but Bobi is one of a kind".

Bobi has lots of friends. Picture by: Guinness World Records

One of the biggest contributing factors to Bobi’s longevity, according to Mr Costa, is the "calm, peaceful environment" he lives in.

Throughout his life, Bobi has freely roamed the forests surrounding his house; he has never been chained or leashed.

Bobi also grew up surrounded by many other animals, so he was never lonely.

Now in his senior years he finds it difficult to walk, so he prefers to hang out at home in the garden.

His eyesight has gotten worse too, which means he often bumps into things when he walks.

Bobi in 2023. Picture by: Guinness World Records

Just like old-aged humans, Bobi also sleeps a lot.

Mr Costa, now aged 38, was just eight when Bobi was born. He said Bobi is a living reminder of the past.

"Bobi is special because looking at him is like remembering the people who were part of our family and unfortunately are no longer here, like my father, my brother, or my grandparents who have already left this world.

"Bobi represents those generations," he added.

Main image: Bobi then and now. Picture by: Guinness World Records