I have had two rat terriers, Pennygirl and Nelly both who died of cardiac failure. They were wonderful dogs. Pennygirl came from puppy mill and lived to be 8 and Nelly was a rescue from an abusive home and lived to be 7. I still miss them both. I would not look for a pedigreed rat, but rather one from a decent breeder. They work well in a family situation or with multiple dogs. They will be a companion dog to whom ever they pick. Penny was mine. She stayed at my side through several surgeries. Nellie was my husband's dog and was always one step behind him. I hope you find you new best friend!