A family at my church is looking to give their golden retriever up for adoption because their 2-month-old baby is allergic to the fur and approached us. Currently, we have a male collie whom we've had since he was about 1 and he's had the freedom of our entire garden to roam and establish his territory. My question is, if we adopt the retriever will that cause problems for the collie? Is it possible for two different to harmoniously live together? As in, will my collie feel threatened by the newcomer's "poaching" of his territory and as a result will I have to anticipant fights? (The retriever is female, so I'm not sure how aggressive over territory or whatever they might be). TIA!