Is it possible for a female dog to have a yeast infection?

My three year old lab-shep mix has been licking at herself and seems to be really frustrated that she can't satisfy this it_ch. She has always done this off and on, but today she is really getting on my nerves. When I tell her to stop, she does but then she sits here panting and just can't seem to get comfortable. I wonder if it's possible for her to have a yeast infection or something similar to it? She has been spayed since the age of 9 months, so I know it isn't like she is coming into heat.

Does anyone have any words of wisdom before I get on the phone to call my vet? I would like to have some kind of idea what I would be calling to explain.

Thanks, doggie lovers.