Has he been wet at all, like swimming or a recent bath? That is what causes Nebo's hot spots. If he doesn't get dried thoroughly the moisture gets trapped near his skin and causes an irritation. I imagine the folds of Chipper's neck would also trap moisture. Hot spots can be caused by a variety of things though. I have some hot spot spray from Petco I use for Nebo and it works pretty well. Hope Chipper gets feeling better soon!