I have two brown leghorn chickens. One seems very healthy and normal but the other began to lose feathers and has recentlybecome very skinny. She is not as active lately either. I though she was molting and left it alone, but I am starting to suspect worms maybe. All the chickens have clean vent areas. I use D.E. in food and coop and have used Wazzine once before.What is the best worming method? Are there other symptons i should look for?