The beagle, Shandon, had been missing for almost three days, the Irish Independent reported. It wandered off while out for a walk with David O'Connor on a path on top of the Fogher Cliffs on the island in southwestern County Kerry.
Shandon's disappearance came on top of another loss for O'Connor and his grandchildren. The dog originally belonged to O'Connor's son, Dan, who died of cancer in August at the age of 36.
"I was very worried about him of course but even more worried someone else would fall off the cliff looking for him," O'Connor told the Independent.
A neighbor alerted Suzanne Gibbons from the Animal Heaven Animal Rescue, who got in touch with the Knightstown Coast Guard. Volunteers looked for the dog because official searches can only be done for people.
Anthony O'Sullivan, who retrieved the dog from the crevice, said he was obviously scared and they could hear him "screeching" as they got close.
"We've taken part in many searches for people, but this was the first one for a dog," O'Sullivan said.