That hurts my heart so much to even think that a golden could be mistreated in ANY way. I cannot even think about such things before my eyes fill up and I feel sick to my stomach. Some human beings do not deserve the unconditional love given by a golden heart.
My golden had a spot like that when he dove under the bed to get a moth and scratched his muzzle! However it was bald for a few weeks then healed up nicely. He is smart: he doesn't let moths lure him under there anymore.