
Hi Noel,
I really feel for you as I know someone who has gone through a similar case of separation anxiety.
Although it is extremely annoying and frustrating, we have to remember that Harry is very anxious and fearful when he does this. I read a book called "Aint Misbehaving" by David Appleby from the Association Of Pet Behavioural Councillors and it had some brilliant ideas.
My friends dog when he looked at the situation, used to follow him about at all times, everywhere he went, sit on his lap etc etc. In fact the maximum length of time the dog could be parted from him visually before it whined was about half an hour.
He had to work on decensitising the dog to things such as when he left the house, when he was in a separate room.
Some of the suggestions were hard to take because he felt he was being mean to the dog where in fact, he was gradually building up the dogs self confidence.
For example he had to not respond to attention seeking behaviour at all times. Touch, voice and eye contact was only given when the dog was relaxed. If the dog came up for continuous attention, he was to just ignore it, and not to physically or vocally reject it. He ( my friend) decided when and where attention sessions were given.
Because the dogs anxiety kicked in at 20 mins abscence he had to work on increasing this time by basically teaching the dog that it was great being on its own and away from him. This is a gradual process. The dog was not allowed to sit on his lap anymore whilst watching telly for example. He had to put the dogs bed at a distance to allow the dog to see that it can relax at distance, then gradually increase the distance. When the dog lay relaxed, he could then give affection. He had to then try leaving the room a few steps at a time. If the dog stayed relaxed, he had to go back and give it attention.
When you read David Applebys book he talks also about relaxation cues to trigger relaxation during your absence. These include things like the radio, television or items as simple as a blanket that are always present when you and your dog are together and the dog is relaxed but you are not interacting. These items such as a blanket are then introduced when you are absent, say in another room with dog behind gate, then when dog is behind closed door, and finally when the dog is left (you've gone out). You then have to remove these items when you return and the dog has access to you. Interestingly things like the radio and telly that the dog associates with relaxation when your present, should be kept on in your absence and when you return, I guess so the dog doesn't associate you leaving with the radio being turned on.
Some other things he suggests is working on leaving the house and coming home. Dogs are very quick to learn that when you put your coat on and pick up your car keys, it means they are going to be left. He suggests performing these things at times when you are not leaving, but just going to wash up or watch telly to desensitise the dog from these departure cues. Attention should be withdrawn half an hour before departure, relaxation items put in place (radio, chews, item of clothing with your scent on), then leave swiftly without speaking. On return, if the dog shows excited excessive greeting behaviour it should be ignored to avoid reinforcing its anxiety.
There are things such as a DAP plug in diffuser and or collar that can sometimes help.
As far as my friends dog is concerned, he certainly saw a difference for the better in his dog. It became a much more relaxed and confident little mutt.
Every case of separation anxiety is different. The stuff Ive written is to do with my friends dog and what Ive read. I would seriously contact a dog behaviouralist. Some are covered under pet insurance. Try The Association Of Pet Behavioural Councillors.
I hope all goes well and good luck.