Be wary of using a *partial* course of antibiotics. It is possible that it will improve the condition, or even appear to cure it, but if it fails to kill it entirely it can come back now resistant to that type of antibiotic. If it seems to help, try getting the rest of the course from a vet (hopefully at a discount since it's a partial). Keep track of the day you started and the dose to tell the vet. I wish your kitties luck!