When I moved to LA with my last Yorkie Candy when I was 18 a lonnng time ago we had a flea infestation. The fleas that bit her would leave the dirt like marks on her that your describing. Maybe that's a cause? I'm back in Illinois and have since had a problem with them (knock on wood) but I thought i'd offer up the suggestion anyhow.
__________________  Chandra, Bailey Blue's mama  |