I have a very mild allergy to cats.
It’s so mild, in fact, that I grew up with a cat in the house and it never bothered me very much.
I always chalked it up to seasonal allergies, so I never even realized I had this pet allergy until recently. My girlfriend moved in six months ago, and she brought her two cats with her. I started to notice getting itchy around the nose and throat more often, but still it wasn’t a big deal. Then she got two more cats, and now it is a big problem. We changed out the air filter, which was old and thin and beyond capacity with animal dander, but that didn’t help very much. We upgraded to HEPA air filters, which take out more than 99% of particulate matter from the air, and that didn’t help much either. Finally we called in an HVAC specialist, who said the system was in good shape, but the ductwork needed a thorough cleaning. These air ducts had never been cleaned, not once in the fifteen years since the house was built, so they were filthy with old dust and dirt. After the ductwork got cleaned out, my allergies went back down to normal levels, so I guess it was not the cats fault. This means that I can’t use the ventilation issue for my argument any longer, which means I’ll have to eventually admit to her that I just don’t like cats very much. Beyond the air quality, and the allergies, I just think cats are little jerks.