vet question

Dear Madame Veterinarian:
Our Siberian has one of the best pedigrees we could've asked for, and fortunately for us, she has been virtually ailment free for the past 13 years. That's why we're shocked to discover she has this horror--degenerative canine myelopathy. She's been treated for arthritis for the past couple of years, but now it's quite apparent that she's toe dragging in the rear, increasingly wobbly, and so on. Her spirits are still rearing to go, however.
We live in japan--in fact she is a JKC dog, but the parents came from a well-regarded kennel in Minnesota. We haven't contacted them yet; we've been in denial, I'm afraid. My questions are: 1) Should we continue the anti-inflammatory regimen even though her disability is obviously much more than hip arthritis? I've begun giving her B12 because I understand that it, along with a couple other supplements, together have had some success with slowing deterioration (Journal of American Veterinary Medicine 1983). 2) Do you know where we could order those supplements? We do have a vet here on this American military base, but her attention is hard to get given the military working dogs here and the off-base Japanese vets might want to do extensive testing etc., which, quite frankly is just not worth the stress on the dog or us financially.( japan is outrageously expensive, especially when ity comes to pets.) 3) Is it safe to give Nim acetaminophen or ibuprophen?
Please do advise. We'll do anything we can to to keep her body in sync with her heart and all her other systems, which are characteristically go-go-go.
Thank you.
I welcome your counsel from so many miles away.
Sincerely,
Mrs. Skeen
Yokota Air Base, Tokyo, Japan.