Try to find a veterinarian in your area who has
digitalDigital rectal exam X-Ray capability. Our practice has
digitalDigital rectal exam X-Rays and we can often visualize bulging disks without having to do an MRI, or myelogram, and the price is reasonable. Also, it would be very valuable to consult a veterinary neurologist.
Since this problem happened so abruptly I would lean toward a disk problem. Disk disease treatment can involve medications such as steroids (acting as anti-inflammatories), muscle relaxers,
acupunctureAcupuncture
Alternative medicine - pain relief, and lastly surgery. Many veterinarians may give medications as a kind of treatment option. If there is a response to treatment, i.e.: if your dog improves on steroids and muscle relaxers than perhaps it was, in fact, a disk disease that was not severe enough to require surgery.
To help you further I would like to ask some questions about your dog so that I will be able to give you the best advice.
1. Did the
tickTick removal titer include: Lyme, Anaplasmia, Erlichia, and Rocky Mounting Spotted Fever?
2. Did the blood test include a T4 test for hypothyroid?
3. What breed is your dog? Is he a Doberman, Rottweiler, or German Shepherd (Alsatian, or Schafferhund)? If he is a mixed breed, can you give me an idea of which breeds are in his ancestry? Wobbler’s disease is more common in the breeds I have listed.
4. Is your dog eating normally and still losing weight, or has his appetite decreased?
5. Has he been vomiting?
6. Does he have diarrhea?
7. Is your dog drinking more than normal? Is your dog urinating more than normal?
8. Does he turn in circles when he tries to walk?
9. Did your veterinarian take any X-Rays of your dog? If he/she has what were the findings?
Any additional information you can give will help.
It might be best to answer the above questions as a new question if possible; otherwise I will answer your question via comments.
Thanks!