I was wondering if anyone has any experience with pectus excavatum in
the mature cat..

I recently adopted a 3-5 year old domestic shorthair mix with an
unusual chest deformity. (The cat also has some minor spinal defects,
which her vet believes she was probably born with.) None of the vets
at our local practice have seen anything like her before, and seem to
think that the most logical explanation for the deformity is that the
cat experienced some sort of traumatic injury at some point.. but
although there is some muscle tightening and possibly scarring at the
indentation site, (the upward shifting area is very hard to the touch)
she doesn't seem to have any evidence of previously broken bones or
corrective surgery that I would think would be necessary if such an
injury were to occur and cause that much lasting damage. And, although
it definitely *feels* as though she is scarred in the area, there is
no scarring actually visible from the outside. So, particularly given
the fact that other birth defects are present, I'm wondering if a
congenital defect like FCK or pectus excavatum might be a more likely
cause. (I don't have any pictures on hand, but if, from the side view,
" \_____/ " were to represent a normal cat, she looks something like
this, " \_/\___/ ", with a sharp indentation underneath after her
breastplate.) The cat was left abandoned in a cardboard box where I
work, so I don't have any history on her.

If it were a defect along the lines of pectus excavatum, what is the
prognosis for an adult cat who seems otherwise healthy? Much of the
information I've found only really discusses kittens.

Thanks!