Re Rigging, Re Targeting same skeleton to different meshes without distortion?

I have used an existing German Sheppard skeleton and animation package and wish to use my own meshes with it, but how might I avoid the stretching I see when I retarget the imported fbx to the original animations ?

It works flawlessly when little or no skeleton manipulation occurs, but when I need to lengthen the neck or legs of the skeleton to fit the new mesh, it stretches and distorts the character.

How might I avoid this ?

Do I need to recreate the skeleton from scratch, but use the same naming convention so that retargeting still works ?

Should I instead create a Control Rig that can be used on all of my four legged models ?

all of which would still use the same skeleton.

I had to move the skeleton and lengthen some bones in order to get it into the shape of the tiger, and doing so it stretches the mesh after retargeting, for obv reasons.

but how do I fix this ? by recreating the skeleton ?

I did a freeze animations on the skeleton in maya just before skinning… but I still get this

rebuilding the skeleton freshly for the tiger mesh worked.

I just renamed the bones to the same names as the original skeleton

now it all works seamlessly. the same control rig works on the tiger.

I am even using PowerIK, but my feet keep swaping to the opposite sides, I need to find a way to constrain them to one side