M.sue :
You might have to look up a vet who specializes in livestock. When making small with our dog's vet he said most generally chicken cases are for vets who specialize in livestock / lrg. breed animals. Go figure, who thought a chicken would be considered a lrg. breed animal.
They don't actually teach much poultry science in vet schools, at least not at MSU, and probably that holds true for most US vet schools. At MSU 30 years ago, when I was a potential pre-vet major (and eventually walked out the door with a degree in English

), they made you take a poutry science class as an undergrad because they covered **nothing** in vet school about poutry. I took that poultry science class, and believe you me, it would not qualify you as a chicken vet (of course at the time, I had *no* idea I'd ever own chickens so maybe I didn't pay enough attention
). I talked to a recent MSU vet school grad and not a lot has changed. So the vets who see chickens have likely done extra study/training on their own. Because a lot of the large animal vets would visit farms that also have chickens, there would be more call for them to brush up on their chicken issues than your basic cat and dog vet.
Another possibliliy is a vet who sees "exotic" pets, including caged birds. They would also be more likely to treat your chicken as a valued pet (if that is how you think of her or him). They would also likely charge more, but offer more options for treatment. But in any case it's certainly wise to know in advance who would see your birds in your area should the need arise.