'bunny-girl' - how is Hooch this morning ?
I can't really add very much to what has already been posted above - particularly from what 'mymatejack' has said.
By the look of the size of the operation site - it looks like your vet is on the ball and excised the whole lump plus allowed for a very clear margin around the lump site. This is very important when looking at these types of things.
Try and not worry too much - but in saying that - we do worry about our pups who we dearly love and wish to protect.
Heaps and Heaps of Good Luck Wishes and for you and Hooch !