You can search for holistic vets at www.holisticvetlist.com. I agree with the others that a diet change may be a good first step... (and ANY food with corn in it should be tossed - cat or dog). Animal Spirit on Mass Ave is a good local place with reputable foods.

I have used Marie Cargill - but for a dog. Not sure anyone would be wise to stick needles in a cat ;) but if anyone does, it's probably her. She is very good and reasonably priced.

Good luck.