I would be worried about pain control- these dogs are very stoic and don't tend to show it- my dog Nick was on metacam (liquid) and tramadol for bad arthritis and worked very well.
can also do cartropen shots.
later with the bone cancer - stronger meds but I let him go run free shortly - VERY different scenerio of course.
also you may want to check into care credit - high interest but helped me out a time or two http://www.carecredit.com/vetmed/
hugs to you and socks-