The thing that concerns me about a dog with seizures is that some of them bite randomly when they aren't "all there". The experience my Aunt had with her cattle dog mix, KC, was heartbreaking. KC had seizures starting at about age 3. Vet said it was epilepsy and he was put on meds. He nipped the kids a few times before and after the worse of his seizures. He also got progressively worse over the next couple years and was maxed out on meds with seizures coming frequently and starting to do brain damage. He had to be put down on Christmas Eve. He had been with the family his whole life and everyone was so sad over the holidays. My concern with a dog missing a limb is the strain it puts on the other limbs. I would be concerned that there would be future joint and tendon problems forcing the removal of the remaining limb or euthanasia.