Sounds like a yeast infection. See your vet.

It's probably yeast build up. You can try off the pet store shelf ear flush fluid and clean her ears with cotton balls. You'll likely wind up at the vet though. It's not an emergency, but will lead to worse problems if not addressed.

I've got a fox terrier with red somewhat itchy ears--just started today. We use Frontline so it isn't fleas--no signs of bites--she does't swim hasn't been in the water--we use Mosquito Squad on the yard so no bites there--but I take her on a 3 mile run (some it through grass) once a day. Is there anything I can do for her at home--not going to schlep in to $$$emergency care tonight--she doesn't seem really uncomfortable --is it just neurotic scratching?