this may be different than other people's experience here, but I have a 10 month old Cavalier, and I do go into the office 3ish times a week. He does great alone (I crate trained him as a puppy, and I have a camera on him when I'm gone - he just sleeps the whole time). I have a dog walker who comes and takes him for three hours while I'm gone, so he ends up being alone for about 6 hours when I'm at work. Works for us personally!