Dog Harness Lifting

How to help a senior overweight dog walk better?
We got her from one of my friends years ago and unfortunately they let her get very overweight. We tried to exercise her but she was too weak and she wouldn’t eat diet food. She is a golden retreiver/lab mix and she is now 15. I know its her last years and we have had really good luck w/ having our dogs last a long time. (my last lab lived until he was 18!) She really likes to take walks but has a hard time standing up from the floor because of her back legs. Also her belly has effected her back I know. I want to make her walks a little better. Are there any back braces or harnesses that would help lift up her belly so that her back is supported? And as far as the back legs, I’ve seen plenty of back leg “lifters”. I jsut need something to support her back and I know she would walk better. She still has a lot of spunk. Thanks.
. How much does this dog weigh? Put her on a diet. Once she loses weight she should be able to walk. My dog Is 128lbs.
She Is a Bull-Mastiff/Am-Staff. It Is possible that because of the weigh that she has permanent damage to her legs. Also
If she Is not walking her muscles could have atrophied. That
Is when the muscles become weak from no exercise.
Dog Support & Rehabilitation Harness by GingerLead