Help my Puppy Jack Beat the Big C

I started this page for my ten-year-old white Boxer Jack when he came down with a severe case of kennel cough last summer (the picture above is before his first hike at Boulder, Colorado's Chautauqua Summer of 2005).

He recovered from that ailment, but this week he temporarily lost the use of both his hind legs.  He's able to walk again, albeit awkwardly, but initial tests are pointing to a neurological problem possibly caused by a spinal tumor (all of his neuropathy is in his lower half).

Those initial tests including x-rays (highlight above) set me back several hundred dollars, and I'm asking for your help to fund further testing (including an MRI and tests for a low thyroid level), and to fund any needed surgery.
I'm a small businessman on a budget, folks, and pet health insurance hasn't been in my budget for years (Jack's getting to be an old dog, and insurance for this breed and age runs into three figures monthly).  Please help with whatever you can, and I pledge to purchase health insurance for Jack if GFM funds can cover it after paying for this condition not covered by insurance...

Thank you for your help, and thank you for reading!