Hello, I'm Dr. Diane and will try to help you with Cola today. Where is she scratching...is it just her ears?
Also, if you look in her ears, are they red? Is there a smell or discharge from them?
Okay, it's good you checked for fleas and parasites b/c that is one common cause for scratching. The other common cause are allergies, either atopy (inhaled allergens like pollen) or food allergy. Here is a link about skin allergies in dogs: http://www.veterinarypartner.com/Content.plx?P=A&S=0&C=0&A=2604 If this is the first time she has had these symptoms, sometimes just an antihistamine will help relieve her itch. If it is a more persistent problem down the road, she may need corticosteroids or allergy testing and allergy injections. There is also a product called Atopica which is sometimes used. Also some dogs develop secondary bacterial infections on their skin from all the scratching and need antibiotics. How much does Cola weigh?
Here is more information about atopy (airborne allergy) and treatment options: http://www.veterinarypartner.com/Content.plx?P=A&S=0&C=0&A=597
Were you able to see my responses? Do you have any further questions about the scratching?