I was brushing Apollo last night and he rolled over onto his back I was brushing his chest when I noticed a HUGE patch of thinning/balding hair! This is the only part of his body that is losing fur. He doesn't seem itchy, dry, red, or irritated in this area. Is this because of the shedding or could it be something like mange? I'm just a paranoid doggy mamma. I wanna make sure my boy is ok. Another thought. Could this be from laying in his urine (he pees and then lays submissivly in his urine) like from ammonia burns?!?!? Its in a weird spot though for it to be that, its on the part of his chest right under his white spot. Help me out guys, should I be worried? whats up with this???