For about 5 days now, my rat Shrieksy has had rapid heavy breathing and a lack of appetite. She's been on 4 ml of Chlor palm twice daily for a week before this started because of a similar incident that happened (after about 3 days she returned to normal.) It's been very cold out recently so the furnace has been running a lot. It's an old furnace that probably hasn't been cleaned out in ages so I worry that it might be that. She's still on Chlor Palm so I can't imagine it being a myco infection. Anyone know what the causes might be?