I have a just over 2 year old male labrador from a puppy he has been left alone and had no problems over the last 6 plus months he jas started barking if we are out in an evening continuesly I have tried several different things radio crate toys puzzles!! I am running out of ideas and options he has been checked over by the vet and he is fine while I'm at work in the day which confuses me alot he is walked 3 miles a day I don't know what else to try he is a big dog and neighbours have complained