Hi Terry and all:
For rehab you can use a long thick soft cloth (as wide as the wide end on a
tie) and hold one end and put the other under the ferret and then up and
hold both ends, one in each hand.  Support the little one while he/she walks
around.  This will help in working the muscles yet give you control enough
to lift the weight.  Also stretch the legs, like leg pushes, and push back
with your hand on the little feet.  You should feel just a bit of pressure
(resistance on the back push) which should get stronger as rehab continues.
You can also put some water (just enough so that your ferret can touch
bottom yet still swim) in the tub and let him/her swim while you closely
monitor.  NEVER EVER leave any ferret in a tub of water or near a tub with
water in it, even for a moment.  If the phone rings, let it or grab a towel
and your ferret(s).
 
Suki may be able to give you some ideas on a cart.
 
Hugs to all. tle
[Posted in FML issue 2011]