3yr old Don Sphynx has really bad URI, vet gave 2 weeks of synulox (amoxicilin) with no improvement, so conuclide it mus be viral. Just started l lysine, for a few days and his symptoms appear to be getting worse. his eyes are clear but hes deeply congested and sneezing considerably more mucus everywhere, and sneezing frequently. does the l lysine make things initially appear to be getting worse? As in, loosening the mucus that’s there? Or will he need other treatment? he hasn’t had any booster jabs for a long time since a kitten.