These days my pomeranian keeps barking unnecessarily and looks at everyone with suspicion. I am not sure if any incident led to this behaviour but I would like to correct it as it wastes a lot of energy and it is inconvenient for us as well.
Your dog might be suffering from some type of depression. You need to find the cause. Have you been frequently staying away from your dog? Try to show more love and affection to him and it may make a difference.