He could be teething?? Our little Chewy is almost 6 months old now and when he started teething, he would not eat the hard food. I usually would mix a little wet food with his puppy food and he would lick the wet food off of the dry food (little booger!!)
All of my yorkies are such picky eaters?? I do sometime top their food with cottage cheese, boiled eggs or shredded chicken so that they will eat it. Our little Chewy has VERY thick hair and he also gets pee on his belly. I bought some puppy wipes at Petsmart and I clean his belly with those everynight. We also used my hubbies clippers to shave some the hair on his belly and this helped alot! Luckily hes a trooper about letting us do it.