I've had my chinchilla, Charlie, for about 2 years now and this morning when I woke up he was acting very strange and making a noise I've never heard him make before. It almost sounds as though he is coughing. I've checked for other symptoms of a cold but he doesn't have any. I thought it could be stress but I can figure out what would be causing it, absolutely nothing has changed about his environment. He is very jumpy and will hardly let me touch him and be keeps staring at the wall beside his cage like he is terrified of it. Any suggestions as to what the problem could be and what I should do?