Our chow chow would also scratch a lot and then start to lose fur so we took her to the vet. The Vet said that it was because of a ticks although she did not have a lot, the scratching was making her lose hair. She was given frontline a once a month flea and tick treatment and a herbal shampoo instead of the commercial brand. The Vet also changed her dog food to a high nutrition one (a.k.a. more expensive one) because according to the vet hairy dogs need more nutrition because their fur needs a lot of vitamins etc. and if they don't get it the skin suffers because it won't have enough nutrition and that may cause hair loss.
