Our Yorkie had this problem. The vet looked at the red spots and said that Beau is sensitive to flea bites. After starting him on Trifexis and switching to a non soap dog shampoo the problem stopped. The shampoo is not available at big discount stores so we buy it at a local pet store. Problem solved. My friends dog was itching because the food she fed Lucy had too much protien in the formula. She switch food and problem solved.