My cat, Meep, has a similar problem, but probably not as bad as your
cat's.  I adopted her at 12 weeks; she's 8 now.  A recent x-ray shows
the bones in her lower legs, below the hocks, are actually slightly
curved, but this isn't visible "outside".  From the side, she looks
normal.  From the back, her hocks point inward, and her lower legs/feet
point outward at just slightly under 45 degrees.

I call her 'cow-hocked', try a google for that.

She gets around fine, but has to swing her hocks out slightly as she
walks so they clear each other properly.  She regularly does vertical
jumps to 3', but I think that might be the extent of her ability - my
last cat could do twice that height.  I would not consider her hind legs
 "weak" but her structure does limit her jumping ability, I think.

She's been diagnosed with a rare condition in cats - luxated patella -
which is where the kneecap slides out from where it's supposed to be.
If it sticks, it'll cause the leg to stick out, or the cat to be
obviously lame, until it goes back - then she's perfectly fine.  She had
a single incident where this was a problem for around a month, then it
corrected.  During that time we kept her confined away from stairs, and
away from most places that she had to jump onto.

We have to keep her weight down to reduce the stress on her legs, and I
worry about arthritis, so we have her on a glucosamine supplement.

FWIW, I've never considered her to be deformed (though some might, I
suppose) but I would say she just has bad conformation.

I guess what I'm saying is if he can get some strength in those hind
legs, he can grow up normally, probably just won't be a world-champion
jumper...fortunately you're catching this young enough that perhaps with
the vet's help his legs can be straightened a bit.

jmc

I am no vet, but I am very concerned that the vet has taped the kitten's
legs that have a circulatory problem already (the fluid-filled feet).

Sharon Talbert
Campus Cats