I dated a girl for a while who owned a cat. I built up a tolerance to her cat (because she'd have the dander on her clothes), but it didn't help with any other

I dated a girl for a while who owned a cat. I built up a tolerance to her cat (because she'd have the dander on her clothes), but it didn't help with any other cats. I was also still allergic to her cat, but it was at the point where a claritin would help. Mostly it's within half an hour I can barely breath, so it's hard to build up any sort of tolerance, even with allergy meds. Now it's easier for me to avoid cats entirely.