My chi also had a short haired mother and long haired father, i asked the breeder i got him from and she said although he has very short hair right now, he will be a very, very fluffy, long haired, white coated dog. He is 5 months, has a dark tanned coat and is very short haired. How she knew this, i have no idea, but ask a proffessional, they really seem to know what to expect and how to tell. That's all i can offer!!