When we brought the two puppies home to Oscar, he was about 1 and 1/2. Oscar had been the only dog for all of his life so we were a little concerned about how he would react...now I can't imagine life without them. They get along great...they are a big handful but they are worth it. The male puppy and Oscar are byfar not as close as Oscar and Mollie Mae. I think it has to do with Oscar being a laid back dog and Eeyore being more...I don't want to say aggressive but more dominant. They fight more than I would like but....we are trying to decide what to do about that. Two males just butt heads...trust me, I've found out. When we first brought them home we thought Oscar would literally walk all over them bacause they were so small and him so big but it was just the opposite. The puppies walked all over him, bit him, scratched him, knawed on him, you name it, he took his beating from them but in the end...here we are. I would recommend getting an opposite sex dog. So if you have a female, get a male....chances are, they will become the best of friends. They love eachother's company and love playing together....a lot of energy is expelled by having more than one dog. Keep in mind also that people give dog's away not always because they are aggressive, maybe they are allergic or have no time for him, maybe they are moving out of the country and can't take him along....who knows why....I would definately ask and spend time with the dog so you know for sure. Good Luck and keep us updated.