My JRT is 7 and has always hurled himself against the front door when I leave. I have bottles and cutlery in a bag hung from the door as a noise deterrent to stop him scrabbling the carpet. Once gone he settles.
This is regardless of why I'm leaving e.g. nipping out to the bins/shop/work
Lately this behaviour has extended to inner doors when anyone leaves. Snarling angry temper tantrum is how I would describe it.
If it's me leaving I can order him back to get out of the door. If others leave, he is told to go to bed. (This is not always consistent because sometimes with DC it's chaos, with them forgetting stuff and coming back for it or opening door unexpectedly and he makes a bid for freedom.....gets shouted at to recall him etc but it is the normal plan)
Today DD left (she's 18) and he did his normal ferocious temper tantrum (I was indoors in the kitchen and about to come out and recall him to bed as soon as I heard him start) but he bit her calf breaking the skin. She left in tears.
I'm pretty sure a behaviourist is the answer and can't afford one. I'm sure you will slate me and tell me I shouldn't have a dog if I can't afford one but recent redundancy/divorce means I'm strapped for cash.
I did look up behaviourists anyway but the nearest is 50 miles away!!! I don't have a car and can't face a bus journey/cost etc
Help :(