My Cats has a skin problem...

Some spots, such as on his right ear would become raw and tender. We took him to our vet, she done a skin test, he dosen't have parasites or mange so she gave him anti biotics, this isn't helping him. Any ideas?

Did your vet test for ringworm? That's a possibility, but this sounds exactly like what my late Siamese kitty, China Cat Sunflower, had at one point.

She was tested for EVERYthing, and it ended up being a bacterial infection on her skin that just wouldn't respond to oral antibiotics. Our solution was this:

I got a special shampoo for her from my vet that contained both a fungicide and an antibacterial, and bathed her three times a week with it. It was called "Vet Solutions Universal Medicated Shampoo". The difference could be seen almost overnight.

And yes it's hard to bathe a cat (China more so than most!) So my vet gave me a mild tranquilizer that I administered about half an hour before bath time. She just sat there in the sink and allowed me to bathe her!

Within a month, she was back to normal. Hope this helped.

Did your vet check to see if this could be ringworm? Its not really a worm but a fungus by the way and dose cause what you describe. Try taking the cat back to the vet or even try another vet.