The poem has been passed between animal lovers since the 1980s. Picture: Wikimedia Commons

Washington - If you've lost a pet, chances are you've heard of the Rainbow Bridge.

This bridge is a mythical overpass said to connect heaven and Earth - and, more to the point, a spot where grieving pet owners reunite for good with their departed furry friends. It is a poem, origins disputed, that launched the pet bereavement movement, inspired countless pet loss blogs and fuelled a lucrative marketplace for rainbow bridge-themed dog urns and lava bead bracelets.

It is, in free verse form, Chicken Soup for the Soul for an exploding $69-billion pet care industry.

The poem has been passed between animal lovers since the 1980s, but its origins are fuzzy. Although it is usually attributed to an unknown author, at least three men claim to have written it - one, Paul C. Dahm, even holds a copyright for a variation. All three wrote similar books in the 1990s on pet loss after claiming to have penned The Rainbow Bridge.

"I wrote what I then called Pet Heaven and forgot about it until 10 years later, when I lost my own dog and heard about Rainbow Bridge, " said one claimant, Wallace Sife, who recalls writing his version for a California friend's dog club newsletter. "It was a modified version of what I had written."

Whatever its origins, the poem and books that followed validated a demographic in need of support and helped create a new social construct - that pet deaths are devastating for people.

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Even professionals have taken solace in the promise of the rainbow bridge. Veterinarian Julie Ann Luiz Adrian, an associate professor at the University of Hawaii, said it comforted her after her cat, Friday, died when Adrian was still a student.

"It talks about the kisses from them, their nose twitching," said Adrian, referring to a line that appears in some versions. "Something in it resonates with people."

And their sorrow is real, said Adrian, who would know. She published a study last year that concluded people follow the same trajectory of grief no matter who or what - human or animal - they are mourning. Almost 30 percent of pet owners reported prolonged grief lasting six months or longer, Adrian found, while 12 percent suffered severe grief that resulted in major life disruption. More than 5 percent suffered post-traumatic stress.

The level of grief was determined by how the owner perceived the animal, Adrian said.

"Was the animal truly part of the family?" she said. "For some of us, and especially for the newer generation who are replacing pets with kids, our pets are our children."

The Washington Post