Sneezy rats

Hi all! So if you have seen some of my other posts floating around on this sub, you will know that I have been constantly having issues with my boys health. They are from a breeder (thought I have been questioning the quality because though she is knowledgeable and has been breeding for over 20 years, she told me I had to use fleece bedding and she uses an ionizer air purifier), have a critter nation cage that is cleaned thoroughly once a week and spot cleaned throughout it, are in aspen bedding that I sift out for two hours a week to make sure it isn’t dusty, though it is still kind of dusty so if you guys have any bedding suggestions that’d be great, and they are on yesterday’s news litter. I clean all fabric including my bedding and clothes in the room with scentless detergent. I never use scented products and frequently dust the room. None the less they have been through two rounds of baytril and doxy for 3 weeks, clavamox for 2 weeks, and SMZ-TMP and echinacea for 2 weeks (continuing the echinacea for 2 more weeks) and probiotic powder in their water daily. Each time their sneezing and even grunting noises come back. I have no idea what to do. I am so worried about them and I feel like I am failing. I feel like I’ve tried everything. Can anyone help? Feel free to ask detailed questions in the comments in case I missed any info. I just want my boys to be happy. via /r/RATS https://ift.tt/2SodtmP