Do you have a 'fossil dog'? TikTokers share the stories of their pets who 'just won't die' despite being over the age of 15 and 'blind, deaf and toothless'

A new trend has exploded across TikTok, with users showcasing their elderly pets in clips and coining them 'fossil dogs' as a way of coping with their beloved pets' mortality.

The hashtag has racked up millions of views on the video-sharing platform as users marvel over their ancient dogs, some of whom seem appear to be clinging on to life.

Many of the pets who feature in the videos have eyes clouded with cataracts, bodies rigid with arthritis and matted fur - but they are undeniably loved.

'When I come home from college to see my 19 year old blind, deaf, toothless dog with dementia that never knows where he is,' one user captioned a video of her graying Dachshund.

Another clip featuring a small black dog with a severe underbite was captioned, 'When I come home and see my 16 year old fossil dog lost three more teeth.'

'When I come home from college to see my 19 year old blind, deaf, toothless dog with dementia that never knows where he is,' one user captioned a video of her graying Dachshund

Another clip showcasing a small black dog with a severe underbite was captioned, 'When I come home and see my 16 year old fossil dog lost three more teeth'

Another college student shared on TikTok that she was 'coming home after college to my 15-year-old fossil dog who's deaf with dementia'

Of course, saying goodbye is inevitable, and for some pet owners, trends like the 'fossil dog' phenomenon can offer solace.

One user's video about her 16-year-old dog, Brutus, had garnered nearly 4 million views at the time of writing.

'Brutus is a paid actor,' the user quipped, noting that the dog she'd grown up with was blind, deaf and 'going into kidney failure.'

And while commenters showered the adorable pooch in praise, calling him a 'baby,'  the video creator seemed acutely aware of reality.

'Don't worry guys, he's on comfort care and a s*** ton of drugs until it's his time,' she wrote.

Another user shared a clip of her boyfriend's parent's 'fossil dog'

Some owners of elderly pets have commented that their dogs 'just won't die'

The fascination with long-lived dogs is nothing new. The Guinness Book of World Records even has an entry for the world's oldest pooch.

That title was most recently held by Bobi, a 31-year-old Rafeiro do Alentejo hailing from Portugal.

According to Leonel Costa, who has lived alongside Bobi ever since he was eight years old, the herding dog was born in 1992.

But Costa's father decided they already had too many animals at home and took the litter to be destroyed.

A few days later, Costa and his brothers were shocked to find Bobi alive, tucked away in a pile of logs. They hid the puppy from their parents until he was too old to be put down.

Costa credited Bobi's longevity to the 'calm, peaceful environment' he lived in, according to a release from Guinness. He was never chained or leashed and ate nly human food.

His 31st birthday celebration in May was attended by more than 100 people and a performing dance troupe. 

'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,' Costa said at the time.

Bobi died in October 2023, at a record-breaking 31 years and 165 days. However, Guinness Book of World Records later rescinded the title, after they could find 'no conclusive evidence which can definitively prove Bobi's date of birth.'

Once the world's oldest dog, Bobi, who lived to the old age of 31, died in October 2023. However, his official world record was later rescinded, after Guinness could find 'no conclusive evidence which can definitively prove Bobi's date of birth'

'Despite outliving every dog in history, his 11,478 days on earth would never be enough for those who loved him,' veterinarian Karen Becker wrote on Facebook to announce his death at the time

'Despite outliving every dog in history, his 11,478 days on earth would never be enough for those who loved him,' veterinarian Karen Becker wrote on Facebook to announce his death at the time.

The oldest dog currently living is Spike, a 23-year-old Chihuahua mix from Ohio. His age was certified by Guinness in late January, right before Bobi snatched the title.

Like Bobi, Spike has an amazing life story. His owner Rita Kimball found him in 2009 after he'd been left in the parking lot of a grocery store.

'He had been shaved up his back, had blood stains around his neck from a chain or rope, and looked pretty rough,' Kimball told Guinness.

Upon learning that the dog had been there for several days, Kimball took Spike - who was already 10 years old at the time - to her farm.

'Spike jumped right in and sat on the seat, as if he knew where we were going. It was meant to be,' Kimball said.

She explained that she named him Spike for his attitude, which mirrors that 'of a big dog.'

Despite weighing just under 13 pounds, the tenacious Chihuahua mix has 'survived multiple attacks' from other animals and 'come back stronger each time.'

Now, Spike, who is nearly blind and partially deaf, lives out his golden days with other animals on the farm.

Before Bobi shattered the record, there was Bluey, a 29-year-old Australian cattle dog who lived from 1910 to 1939.

Bluey, a 29-year-old Australian cattle dog who lived from 1910 to 1939, was the previous record holder before Bobbi, a distinction she carried for 83 years

Bluey was honored by a mural in her hometown of Rochester, Victoria

She held the record of longest-living dog for 83 years and is honored by a mural in her hometown of Rochester, Victoria.

Of course, what makes the record so impressive is fact that most dogs don't live to see beyond their 20th birthday.

You may have heard that smaller dogs generally live longer. This assertion is generally supported by data.

Toy-sized breeds like Chihuahuas, Yorkies and Maltese typically live between 14 and 16 years.

This figure only decreases with size. Medium-sized dogs like retrievers typically live 10 to 12 years, while massive breeds like Great Danes and Saint Bernards usually only live seven to 10.

While this trend isn't fully understood by scientists, a 2023 study published in the American Naturalist found larger breeds may be susceptible to cancer because of selective breeding practices.

'The dog breed life span–body size relationship may be the result of the evolution of greater defense against cancer lagging behind the rapid increase in body size during recent breed establishment,' researchers wrote.

Nearly half of elderly dogs over the age of 10 will develop cancer, according to the American Veterinary Society.

Dogs develop cancer at roughly the same rate as humans, and this is only made worse by inbreeding.

A 2021 study published in Canine Medicine and Genetics found that the majority of canine breeds are highly inbred, leading to health complications.

'While previous studies have shown that small dogs live longer than large dogs, no one had previously reported on morbidity,' veterinary geneticist Danika Bannasch said in a release from University of California, Davis, whose researchers led the study.

'This study revealed that if dogs are of smaller size and not inbred, they are much healthier than larger dogs with high inbreeding.'

The average rate of inbreeding based on a genetic analysis of 227 breeds was close to 25 percent - the equivalent of sharing the same genetic material with a full sibling.

In comparison, high levels of inbreeding in humans top out at between three and six percent. This has been associated with an increased prevalence of genetic disorders like hearing loss and limb malformations.

Other factors that may impact lifespan, according to research, are gender - female dogs typically live longer than males - and snout size. 

Owners should also make sure their dogs get the core vaccinations like rabies and canine distemper virus. 

Vaccines for other diseases like leptospirosis and Bordetella are something to consider, depending on a dog's lifestyle and the amount of time spent around other animals.

Other steps to take are regular dental checkups, as poor oral health can cause, or be caused by, other health problems.

And seeing as obesity can decrease a dog's lifespan by over two years, it is important to keep them healthy and ensure they get enough exercise.