This is actually exactly what Poppy looked like when I first got her. Same thing it sounds like, she wasn't itchy or acting odd at all, just looked awful and just kept getting more spotty. It turned out to be a some sort of staph/skin infection (can be caused by anything really- allergy, stress, lowered immune response, etc) . I went to the vet and they put Poppy on two weeks of antibiotics, a special shampoo used every three days for 3 days (they need to sit with the shampoo on for a good 10 minutes), then a spray to use every three days for 3 days after that (I believe it was Douxo Chlorhexidine). It certainly worked like a charm although I did use some coconut oil as well just so the bath every three days didn't irritate her skin (just put a little on your hand and give a good massage). Good Luck, let us know how it goes and what your vet says