I have never had this issue with my dog and cant help with the medical side of it. I just wanted to say dont beat yourself up. You were including your dog in your family activites, that is being a good owner. You didnt leave her at home locked in a kennel or chained in the back yard.
Accidents happen and I am so sorry it happend. As far as fence fighting, I know your pain, I have a GSD that will do that too. She has gotten allot better. I just have to make sure that when she is in the front yard I am there with her, and can recall her.
I wish you lots of luck and hope that she gets better soon and can continue her active lifestyle with you and your family.