Thanks to all who have rendered their support. As I mentioned, this could have been alleviated very simply with the Delta supervisor managing the situation and educating the flight attendant that because of the ADA this guide dog was allowed on the plane in her assigned seat. The supervisor could also have reassured this flight attendant that a guide dog (or any service animal is expected to be) well behaved and not going to disturb her or any other passenger. Training from the top down would be helpful in this situation so that it doesn't get to the point that ours did. If you would like to send a letter to Delta to share this experience (or others you might have had) their address is:
Delta Airlines, Corporate Customer Care, PO Box 20980, Department 980, Atlanta, GA 30320, Fax 888-286-3163 or phone: 404-715-2600. I was on Flight # 4693 from Portland to SLC. I do believe it is my responsibility to continue to educate in an assertive way so that these kind of situations can be a thing of the past! After one of these experiences, I always want to make an effort so that the chance of it happening to someone else is lessened.