here's a question, what makes you think they have an RI?
if it's just because they're whistling then they're probably just being carpets... all mine do this and it is well documented that they will make a noise from time to time that many people (including vets) fear is the first symptoms of an RI. obviously its not good to give antiobiotics when they arent needed so i'd tread carefully there.
if i'm way off from your current situation then just disregard
