Is your harness a perfect fit?
No, that's a "problem" too, although I think the "problem" is not with the harness, it's with the dog. The dog is a front limb amputee, so he has a nub where his shoulder should be. The harness slides up toward his neck over the nub because his body isn't structurally able to keep the girth strap behind his missing shoulder joint. He has very short, fine fur so I do appreciate that the padding keeps the straps from rubbing on and irritating his skin.
How does the PerfectFit Harness benefit your dog?
This harness might benefit him more if it could be modified so that there's some extra piece holding the girth strap in place so it doesn't slide up over his nub.