I have a four month dobe which i plan to show, recently she damaged leg while playing and requires an op to correct it. Will i still be able to show, as it does not affect the natural conformation of the dog or will i have to seek kc permisson?

I don't see why the KC wouldn't grant permission to show afterwards. They were quite happy to grant permission for my dog to continue after he'd had a toe amputated.
:)