I'm so sorry to hear this. My cat Sky has been having a lot of coughing/sneezing and now his right eye is always tearing up. He also scared me one night because he couldn't stop coughing. In the past he was diagnosed with mild asthma. Do you think that Magic might have asthma? Sky is now on a low dose of allergy medication which seems to help him a little bit but if he gets startled he'll have some of his coughing/sneezing attacks. This year has been very bad for allergies. I never have to take anything for my allergies and this year I now have to. What kind of litter do you use? If it's scented then I'd change it to an unscented kind. Sky is very sensitive to scented litter and so am I so I've been using Dr. Elsey's Unscented Precious Cat Clumping Litter for quite a while now. If I try any kind of scented litter, even those with very mild scents, I notice that Sky will have more coughing/sneezing attacks. Good luck.