My 17 week old Sphynx kitten still has a stuffy and snotty nose after 4 weeks. He eat good and plays a lot. He has been through 2 different antibiotic and he is on vitamins and Lysine daily. Should he not be getting better by now? I have another vet appointment May 17. But could it be something else? My other cat has not caught a Resp. Infection yet.