Here is what my wife did (not the commentor though). She had dogs growing up, went away to school and developed an allergy. We bought a dog and she would take

Here is what my wife did (not the commentor though). She had dogs growing up, went away to school and developed an allergy. We bought a dog and she would take allergy pills each day but eventually starting cutting the dose as time went on. Now the allergy is gone. For you, I would say visit your friends with cats often, at first taking an allergy pill before hand. Continue with frequent visits and cutting the dosage down. After you cut out the pill completely, make sure to continue to visit.