My 4-year-old Flemish Giant sounds a little congested when she exhales. I also noticed a bald patch under her chin surrounded by wet fur. No previous health issues that I know of (she was a rescue at around 1 year old). She is still eating although possibly a little less than usual. Her hay seems to be largely untouched, and she sometimes leaves a little salad behind, but she still eats pellets and treats normally. No other strange behavior or problems. The only recent change in her life was that we got some backyard chickens, but she's a house bun and hasn't been out to see them or anything. Please let me know if you've had a similar experience and what the outcome was.