I would keep all of the pets I had before we got married.

He would take his impossible-to-housetrain, neurotic dachshund. (Can you tell I am a tad bit bitter about that dog??)

As for Rosie ... I bought her for Joe for a birthday present, 5 months before we were married. But, since he's at work all day and I'm home all day, I raised her. And actually, for all intents and purposes, she is my son's dog. He LOVES that dog, and she LOVES him. So, technically she's my husband's dog, as she was a gift, but she attached herself to my son so completely. So, I think I would keep her.