I have an 8 year old German Shepard/Retriver mix. She has a seizure disorder and hypothyroidism. Just recently she started having hind leg weekness. I decreased her seizure medicine thinking this might be the cause. I had bloodwork done and all her medications are in the therapeutic range. My vet tried putting her on some arthritis med but that did not help either. She is very unsteady on her feet, her back legs cross at times, and she falls easily. She has no stability. I am taking her back to the Vet this week. I am afraid she may have some kind of degenerative spine disease or tumor. Anyone have any experience with this. It is so frustrating and heartbreaking!!!