Pom I checked out a few sites that have doggie wheelchairs but don't look like the usual bulky type.
Anyhow I couldn't seem to be able to copy and paste the site so I wrote it down.

Dachshundswheelchair.com

DogWheelchairsfor small dogs

Two different ones to check out and they will probably lead to other sites you might want to check out. I hope Myndi will do an about turn and get those legs going but it sounds more like her back--keep me posted about what the vet says, anxious to hear, I hate it when they get older give Myndi some extra and hugs from me.