Calling photoshop gurus.

[Lani]

I did a shoot the other day of this charming, very active young dog , and consequently one of my favourite shots managed to nip off his front paw.... which is right at the edge of the shot.
I was thinking it may be possible to extend the canvas a bit, then clone some of his other paw to replace it?
I am not sure how to go about it though, anyone know how to or know of a tutorial which would show me ?

Thanks in advance if you can help.