Unfortunately I know something about unheard of diseases. I once ended up with a terrible, virulent, and until then undiagnosed and unidentified viral infection in my dairy goats. I eventually lost my entire kid crop that year. Every single kid. I spent so much time at the UC Davis large animal veterinary school I knew every patient in the large animal barn. I was even asked if I wanted the disease named after me. I declined.Unheard of diseases are always the worst. I did all sorts of research before buying my GSD and thought I was such a good new owner. I get my puppy home and noticed his eyes seemed to water a lot. I thought it was because of the dust in the air and ignored it, its always dusty here. Almost a year later I looked closer at his eyes and noticed his eyes were covered in a dark film. Rushed him to the vet. Turns out he had Pannus and I ignored it, letting it progress to near blindness. I felt horrible, and still do.
Nothing you did was bad, you gave Sidney a great life. Even up to the end she was loved. You're a good person and she knew that. Her spirit is still with you, alive in all her siblings and your hearts.
Thank you Homesteader.Thank you for sharing about this issue, best wishes and thoughts from another Heeler family