I am looking for a dog that can watch my house while I am at school, interact well with other dogs, and likes to run and have fun. I have a dog now that does all of these very well, but he is old now and can't take walks and stuff with my mom. So we need a dog that can do all of these things and play with my dog and my cat. I want the dog to start small as a puppy but then it has to grow into a big dog. I was thinking of a Golden Retriever, but I don't know if there are any other dogs that I might be interested in. Please tell me what I might want.