Ivan has a bit of a hoarse voice. He can purr and and rumble, but he squeaked two times to Cookie last night and it sounded hoarse. He isn't lethargic, he eats his fave treats and he drinks water. What could be wrong? Is he talking to Cookie too much? I don't think it's URI, his bowel movements are normal, and I clean his cage out weekly and pick up any soiled material daily. I also wipe his cage daily. I'm confused and worried. 