I have a lop rabbit that we've had almost 6 years. Don't know how old she is as she showed up in our yard one day. Anyway, this summer she started making a little bit of a wheezing sound. No other symptoms. Eating fine, eyes clear, no nose drainage. But this sound isn't going away and not getting worse. Should I be concerned? Does anyone have any suggestions? She gets alfalfa rabbit pellets at night, has hay to pick at all the time, gets a papaya tablet and lettuce leaf each morning and has access to water 24/7.