Get Your Dog Care Questions Answered by Experts
Salt and pepper granules...and if you look real close very, very small little worms...is flea dirt/blood and larva.
The crust can be secondary to the skin irritation.
To confirm you can take to a vet...my recommendation is to treat the dog with a good topical like Advantage or Frontline. Treat the house, and purchase a good shampoo for the dog.