Leg mite, lice and pnuemonia

[lucyjane]

I have 10 mature hens and 1 great rooster in my established flock. We had a very severe winter here in Kentucky and my chickens were confined to the coop for days at a time. I did not notice until three weeks ago that three of my hens had a bad case of leg mites. I have followed protocol in treating the leg mites and the flock is recovering nicely. When I was treating one of the hens on the 23rd of March , I notices one of my hens rattled when she breathed. I separated her from the flock and observed her for a couple of days. Her eating, poop, egg production and behavior is normal except for the breathing sounds. She is missing some wing feathers and seems slightly thinner than in the fall. I looked up pneumonia and similar illnesses online but she does not exhibit any runny nose or eyes. What could be wrong with our girl?
Also, I was wondering if I should use a bedbug or lice fogger for the coop. I have washed their feet and put Vicks Vapo rub on them and then Sunday I washed their feet and put bag balm on their legs and Sevin under their wings. I also used Sevin in the coop after I cleaned it each time. Egg production is normal but we are not eating the eggs. Also I put a dose of irithomyacin (I think I spelled it wrong) on them the first round of treatment. It was a drop in formula that I got at the feed store.
We really love our birds and want to provide the best care for them. Any advice would be greatly appreciated. They are out foraging and we supplement with feed as well. I am hoping the spring weather helps us all feel better.
Thanks for you help.