Dogs are pack animals & shouldn't be left alone imo. Our neighbor has a pommie & she cries all day long. So sad, sometimes mine will call out to her as if to say, 'Hi there, don't be lonely & sad...we're right here'

She'll be quiet for a few minutes & start her crying again.
When we first got Mimi, she wasn't left alone much (I always took her to work w/me), but she was a totally different dog after we got Momo. She was soo much happier.