The definition of Dog heaven is clear enough: biscuit without bottom, walking-on-demand, squirrels you can actually catch.

Whether it exists is a thorny question. But according to a new study, owners of all types of pets have become more likely to believe in the afterlife of pets – and they have used tombstones and memorials to express their belief that they will one day meet.

a New analysis Posted in Antiquity MagazineBy studying the history of pet cemeteries in Newcastle and London over a 100-year period from 1881, I found an increase in the percentage of graves that indicated immortal animal spirits.

“Few of the nineteenth-century tombstones indicate an afterlife, although some may ‘hope’ to see their loved ones again,” said Dr. Eric Tourini, the study author, who looked at more than 1,000 animal tombstones. “By the middle of the twentieth century, a greater proportion of animal tombstones indicate that angels await their reunion in the afterlife.”

Pictures of tombstones included in the paper show simple nineteenth-century references to “Topsey, A Loving Friend,” “Our Lear Butcha,” and “Darling Fluff.” In the few instances where an afterlife is referred to, the angel is careful not to challenge contemporary Christian orthodoxy and merely suggests the hope of reunification.

But by the 1950s, the owner of Denny, the “brave little cat,” added firmly: “God bless until we meet again.” At the same age, religious references became more and more common – with symbols such as crosses and “elegies calling for the care and protection of God.”

Tourini, a lecturer in historical archeology at the University of Newcastle, came to other evidence that pet owners were more likely to view animals as part of the family. He wrote that an increasing number of tombstones use family names after World War II – although “some people who adopted the earliest surnames put them in parentheses or quotes, as if they were admitting that they were not full members of the family.”

It was also found that owners often refer to themselves increasingly through family pronouns such as “Mummy,” “Dad,” or “Auntie.”

Tourini said that although difficult to quantify precisely, most stones “are likely to be dogs” – but the proportion of cats and other animals has grown over the course of the 20th century.

Tombstones in four pet cemeteries examined cover burials from the 1880s to the 1980s. Since then, cremation has become more and more popular for those who want to celebrate the death of their pet.

Taurini – who has only owned two goldfish himself but has recently adopted two cats, who will arrive next week – told the Guardian that one of the most prominent recent trends is that jurisdictions across Britain “allow people and animals to be buried together. For the first time”.

Other modern pet memorial services include clay paw prints, framed collars, and even a chance to turn their ashes into a diamond. But many owners still opt for the simpler approach to burying them in the backyard – or the euphemistically called “mass pet cremation.”

While religious views differ around the world, Christianity has traditionally held that animals have no hope for an afterlife. But Pope John Paul II said in 1990 that animals have souls and are “as close to God as humans.”

Some pet lovers saw Statements by Pope Francis in 2014 As giving more hope to furry immortality. He said, “What awaits us … is not an annihilation of the universe and everything that surrounds us. Rather, it brings everything to perfection of existence, truth and beauty.”