I agree, if you don't feel comfortable with the vet, find another one for your dear one. Would you listen to a doctor who didn't seem to take any notice of your health problems or would you go out of your way to find one that cared about you? Since our furkids can't do that for themselves, they depend on us to do that for them. If your gut is telling you that your baby has something else wrong with him, listen to it. If you are comfortable that it is a URI and that the antibiotics will help, go with that.

Personally I don't love my vet, but I live in a very small town. There are only two choices and I had a bad experience with the other one when he was my vet. I guess because it is such a small practice or because I'm there so often, I can get in or talk to the vet any time I need to. I also do a lot of my own research so that I can be as knowledgeable as possible when I go in there.