Just curious if anyone has tried using one before, and if it was effective? More specifically, I am interested in the utility of one for a pup that has minimal to no use of his hind legs? Do dogs seem to adjust and do well with them? Are dogs able to void (use the bathroom) as they need to with wheelchairs? I am not opposed to trying one with my dog should he need one, but am very concerned about his quality of life ... Thanks.