And while you may not have changed their food, their food may have changed! Discovered that issue ourselves several months ago. Suddenly dogs started shedding horribly, scratching, etc. No bugs, no other problems. Packaging had changed on the food. And, although everyone told us the food had not changed - just the packaging - when we changed food, the problem went away. I hate it when manufacturers do things like that. With any products or them or us.