My 5 1/2 month old hen, Penny, has been breathing somewhat louder than usual for nearly a week now and sneezing for about two or three days. She has no other symptoms and seems to be in great health. (My other hen, Henrietta, spent nearly a week inside the house in the shower because she was dealing with sour crop and an infection but is back to great health and is back in the coop/run with Penny). The coop and run have pine shavings and the only main difference that I can think of is that I dusted with poultry dust (Permethrin) about a week or so ago. It's been in the high 80's and it's always pretty dry here so my backyard tends to be dusty. Could the permethrin, dust, or the pine shavings be causing her to sneeze? Her eyes and face are healthy looking, no nasal discharge, no swelling, and she has been eating and drinking as normal. The sneezing just concerns me. Any ideas? Here's a little more background info in case it helps... My girls are on layer pellets and have free choice for grit and oyster shells. Penny hasn't laid any eggs yet but her comb and wattles have just turned bright red and her vent is getting bigger, so hopefully that will come soon. There are two different waterers in the coop, and she gets occasional treats of sunflower seeds and mealworms. She pecks the ground so hard and fast for the sunflower seeds that she seems to sneeze mainly after she eats them, but has sneezed here and there at other times. I have no idea if my girls were vaccinated. I got them just over three works ago from a meat/egg facility. They both have clipped beaks. They had lice, but the permethrin dust seemed to take care of that. We have multiple wild birds around the area... Parrots, mourning doves, finches, western scrub jays, and a few others. I figure this is how they got the lice in the first place. Their coop is well ventilated and I clean it often. It did rain before Henrietta got sick and before Penny's sneezing started.