Minnie and Bruce: True Friendship

Last summer, Minnie the Newfoundland would jump into the pool and save/catch Bruce the Bull frog, hold him in her mouth, swim to the steps and spit him out. There they would lay down beside each other. After sometime, Bruce would escape and the next day he'd be back in the pool. So again Minnie "saved" him, swam, spit him out and let him go and they laid down together. This happened daily for weeks. Some times Minnie would let her go in the yard, some times by the bushes. But always laid down next to the frog and required the frog to lay down next to her. We tried letting him go in the woods but he'd come back. We tried letting him go in the neighbors yard but he came back. Finally we took Bruce to a river 10 min walk down a hill. The next day he was back again! By the end of the summer, we really intervened - we took Bruce to a frog pond miles away- where he could survive, bury down over the winter. And sadly their amazing friendship came to an end. But what are the odds Bruce just might show up this Spring???