In the past week, I've heard one of my BP's make a faint whistling sound when exhaling. I'm scared that it might be a RI, and was going to take her in after the first time it happened if she kept making the sound. The next time I had her out (I believe it was later that day), she didn't make any sounds at all, so I dismissed it thinking something potentially had been partially blocking her airway. A few days to a week later I have her out again, and she makes the same sound. Has anyone experienced this before? I don't believe she is going into shed, and she has eaten for me twice since it started happening. I've had her out many times in between hearing it the first and second time without any problems. Temps: 90/80, Humidity in the mid 70's. I did notice her water was a bit dirty today, so I cleaned her dish, and she immediately went to drink from it. I've heard no gurgling, I've noticed no open mouth breathing, and I've seen no saliva/snot or anything else that could be a RI.