I am SO sorry for the diagnosis of your GSD. I lost mine to DM in 2008. As far as I know--Eddie's Wheels http://eddieswheels.com/products/degenerative-myelopathy/ is the best wheelchair for a dog with DM. It's the only one (that I know of) that will shift support when the disease starts moving to the front legs. YOU HAVE TO MEASURE AND REMEASURE YOUR PUP TO GET EXACT MEASUREMENTS--VERY IMPORTANT. My dog adjusted to the wheelchair easily and I was so happy I gave him that extra time of movement/playing--it was worth the money--I'd do it again for the extra time I had with him. Tears are flowing as I write this--it will be a "roller coaster" for you, so be prepared. Know that this disease affects dogs differently--sometimes the progression is slower in some, but the prognosis is always the same---there is no cure. I found a LOT of support and help (check out the "files") in the Yahoo Group: Degenerative Myelopathy https://groups.yahoo.com/neo/groups/degenerativemyelopathylist/info Please join it, if nothing else than to be able to talk to others--don't be afraid to ask questions. There is no cure for DM, but there are things to try that seem to help with some dogs. You may need a sling to help move your GSD around (or maybe that's what you mean by a "rear lift"??)---- some of the items on this site may help: http://www.handicappedpets.com/ Good luck and please give your dog a big hug from my Angel Chance and me.