The first thing we did was take her to the vet.  No chip and not much
wrong with her besides malnutrition and evidence of severe flea
infestation.  The vet didn't notice the short legs and neither did we
until she started to get along with our old cat and we could tell the
difference.  Her legs are about half length, and not the 1/3 length
that describes Munchkin.  She doesn't seem to have any mobility
problems and she can routinely jump up into a flourecent light fixture
from the bathroom counter top.  This is 4ft 9 in. jump nearly straight
up, and our other cat never made such a jump.  I've never seen her jump
it, but I've seen her up there several times and she has dumped the
light difuser several times, so she has to do it somehow.  She has a
normal length body and is as long as our other cat, but when she walks
she is 2-3 inches shorter.

Our last cat turned out to be our $300.00 free stray.  She came with
ear problems and an infection, but this one has been cheap by
comparison.

Most mutations are bad, but not all.  You just have to look at
something like a ferret to tell that shorter legs can have selective
advantage at times.  It just depends on what mutations you are working
with.

Ron Okimoto