Pet Insurance for my Dog?

My lab mix most likely needs a tail amputation (for medical reasons NOT aesthetic purposes. Her tail is adorable and it will be a great loss). I understand that this is a really in-depth procedure. The estimate from my vet is between $500 and $700 depending on the length of the surgery and complications that may arise. My question is, would pet insurance cover a surgery like this? My dog does not need this right away, so I would be able to wait until coverage started before scheduling the surgery. I'm not sure if this would be considered a pre-existing condition, though. She was not born with this condition, but it currently exists (while she is not covered by insurance). She has "happy tail syndrome" and keeps splitting it open while wagging; it's not healing, so, according to my vet and a second opinion, the next step is surgery.