The fact that this puppy likes to leap out into the garden early and loudly express his delight at the new day is fine for a puppy. It is not fine for the neighbours who are human beings and need their sleep. It is impossible to believe that the owners have not clocked the fact that he is noisy and worked out that it might wake someone.
Getting into dispute with neighbours is a disaster - but, I am sure it can be broached politely and tactfully; although I have to say, you should not be put in a position where you have to do this. The owners should have the brain to work out that it is a disturbance to others.
What were the first ever records that you bought and when?
Parents-in-Law. What do/did you call them?