sprayed female still sexually active

Question
Hello,
I have a 3 year old lab mix, she had not been spayed when I adopted her at 2.5 years. I had her spayed right away (in May), but she has just begun exhibiting classic signs of being in heat, restless, dragging her bottom, swollen vaginal lips (no blood, but discharge) and <gladly> welcomed the attentions of a male at the dog park yesterday. I mean, she was ecstatic. They were happily copulating, full penetration, although there was no tie (he had been proud cut). I stepped in, but the rest of the males at the park all were clamoring for a chance. I was pretty surprised, since I had expected a spayed female to vigorously reject such overtures, at least sit down. I'm taking her into the vet who spayed her tomorrow, in case oworms, infections, etc, are the problem, but don't know whether this is a big deal or not. She was at a breeder's for the first 2.5 years, and would have had a litter this year, but their family circumstances forced a sale. She was around many breeding bitches, intact males and lots of puppies, so I expect that some of this is learned. Could some of her estrogen still be flowing, thus triggering a "faux heat"? Also, should I be concerned about her copulatory behavior? Could it hurt her if she isn't well lubricated by the blood that's part of a normal heat? It doesn't strike me as something I should allow at the dog park, given the level of excitement and riot it incites... I'm no prude, but want to be responsible for my girl and others, including kids that might get knocked about in the melee.
Thanks for any insight...

Answer
Hi Joan

Once a female has been spayed, that's it. She shouldn't experience another season, and so not be interested in a reproducing.  Animals breed for procreation not recreation so unless Mother Nature is giving them the green light, there would be no reason to play that came.

Find out what was removed when your vet did the spay. Then I would have the vet check for chronic endometritis or an infection. Otherwise....he forgot something and she really isn't spayed.

Good luck.