sick rats?

Question
"Hi

I have had my rats for about 2 months now, they are both female and are now around 3 and a half months old. They seem to be perfectly healthy (drinking, eating and are active), however they both keep sneezing and snuffling. At first it was just one who was sneezing a lot and as soon as i heard her snuffling i took them both straight to the vet and she went on a course of antibiotics and that seemed to clear up the snuffling but not the sneezing, the vet said that she was probably just a rat who sneezes often and not to worry. I change their litter tray every day so i don't think it's ammonia build up. I haven't seen any signs of porphyrin in either rat. However lately they both seem to be sneezing and i have heard some snuffling sounds, but still no signs of porphyrin and they both seem completely happy. The area around their cage is quite dusty at the moment as the vacuum cleaner in my house has broken at the moment (but my mum is bringing one up tomorrow as i live at university, so i should be able to sort this out). Because of the dust around their cage i let them out to run around my whole room most of the day to try and keep them away from the dust. Also because i am currently at university and have only just started back the rats recently moved house to come with me so i'm not sure if that was making it worse. I was just wondering if you think it is worth me stressing them out by taking them to the vet and putting them on another course of antibiotics which seemed to stress them out quite a lot last time, or whether it would be a better to leave them be for now and see how it goes? i'm confused because this is the first time i have ever had pet rats (although i have kept other rodents as pets with no problems). Any advice you would be able to give me would be much appreciated :D

thanks

Cayleigh"

Answer
Hello,
what type of bedding are you using? cedar and pine are known to cause allergies in small animals. If you aren't using those bedding I want you to read up on an article I'm about to give and see if their ailments match. The first one is on mycoplasma which is a common infection among rats. Throughout the rats life there will be flareups and antibiotics will help but generally they don't kill the bacteria that cauuses this.
http://peteducation.com/article.cfm?cls=18&cat=1804&articleid=2905

I think your rats may have this disease, but i'm not a vet and only a vet could truly confirm it. I'd take the article with you though.