A few days ago I noticed a hen sneezing in one of my flocks. Everyone seemed so healthy otherwise, I thought it might be just something caught in her beak. In fact, I didn't notice her sneezing again for a couple of days. Then, I heard her sneezing again, often. I have separated her and put VetRx in her water, on her nostrils, and in her beak. The rest of her flock got VetRx in their water, too. But this evening, I noticed several sneezes in that flock. Otherwise, everyone looks very healthy- in fact, I was just noticing how nice this flock looked before the sneezing started. The are all molting but have been coming through molt nicely. Now I'm very worried something contagious might be starting on my farm that will harm or wipe out my flocks. Is there any way to tell what is affecting them at this point? Any way to treat? More info that might or might not be relevant - I just did a major coop cleaning about a week ago, complete with thorough wash down of the inside. The hen that started sneezing first was purchased early this summer from a breeder as an adult. She was quarantined for about 6 weeks before I integrated her with the flock and this is the first health trouble I've had from her.