The Rainbow Bridge poem is used to bring comfort to someone whose pet has died. The poem indicates that a person's lost pet will wait for them at the Rainbow Bridge, and when the human passes, they will cross the bridge together.
There are many variations of the Rainbow Bridge poem. The poem generally suggests that a pet that has passed goes to the Rainbow Bridge, similar to the concept of Heaven in Christianity. When the pet's owner passes, they are reunited with their pet, and both cross the Rainbow Bridge together.
The original author of the Rainbow Bridge poem is unknown. Estimates suggest that it was written sometime between 1980 and 1992. Concepts similar to the Rainbow Bridge are found in "Beautiful Joe's Paradise" by Margaret Marshall Saunders. In the story, deceased animals help each other and work to recover from abuse in their life on earth.