I actually used to be allergic to cats, really bad! Since I clean carpets n' stuff for a living, I'm always going into homes with pets, & cats would kill it for me. I'd be dripping from my eyes & nose, sneezing like a madman, & would have to go outside to recover while my dad would work by his lonesome. However, when my brother divorced his first wife, he moved in with us, & had 2 cats. Those cats stayed in his room most of the time. I'm pretty sure I was slightly allergic at times when he moved him, but either way, I deffinitely developed an immunity to them. Now my wife & I have cats, I have zero problems around them. Wish I could say the same for pollen!