The Rainbow Bridge is the theme of a work of poetic prose
written some time between 1980 and 1992, whose original creator is unknown.
The theme is of a mythological place to which a pet goes upon its death,
later to be reunited with its owner. It has gained wide popularity amongst
animal lovers who have lost a pet. Although no major religion specifically
refers to such a place for pets, the belief shows similarities with the
Bifröst bridge of Norse Mythology.
The story tells of a green meadow paradise located just
outside of Heaven before one enters into it. Rainbow Bridge is both the
name of the meadow and an adjoining bridge connecting it to Heaven. When
a pet dies, it goes to the meadow, having its body cured of any illnesses,
frailties or injuries. The pet runs around and plays with other pets, missing
only one thing – the love and companionship of its owner who is still
on earth.
One day, upon the pet owner's death, the owner crosses the meadow on his/her
journey toward Heaven. The pet spots its owner and runs to greet him. The
pet and owner reunite, and cross the Rainbow Bridge together into Heaven,
never again to be parted.

Just this side of heaven is a place called Rainbow Bridge.
When an animal dies that has been especially close to someone here, that
pet goes to Rainbow Bridge. There are meadows and hills for all of our special
friends so they can run and play together. There is plenty of food, water
and sunshine, and our friends are warm and comfortable.
All the animals who had been ill and old are restored to health and vigor.
Those who were hurt or maimed are made whole and strong again, just as we
remember them in our dreams of days and times gone by. The animals are happy
and content, except for one small thing; they each miss someone very special
to them, who had to be left behind.
They all run and play together, but the day comes when one suddenly stops
and looks into the distance. His bright eyes are intent. His eager body
quivers.
Suddenly he begins to run from the group, flying over the green grass, his
legs carrying him faster and faster.
You have been spotted, and when you and your special friend finally meet, you cling together in joyous reunion, never to be parted again. The happy kisses rain upon your face; your hands again caress the beloved head, and you look once more into the trusting eyes of your pet, so long gone from your life but never absent from your heart.
Then you cross Rainbow Bridge together and enter the gateway of Heaven, never again to be parted.
Author unknown