Olde English Bulldogge

[Karen]

Let us know how it goes with her spay, and whether that helps eliminate the new aggression, as it likely will!

[B&Baussies]

This is not anything that I have any experience personally but someone who replied to one of my posts about neutering my males dog said this “In males, I have seen no difference in temperament after the male has been neutered (in other words I'd tend to agree with your vet, that neutering a dog who has developed hormonal behaviours will not make the dog any better after the hormones are cut off -- they have to be cut off before the hormones have already started to take affect on the temperament -- hence why we see some late-neutered studs who will still try to breed females). I HAVE seen some signifigant changes in FEMALES who were spayed after showing bad hormonal behaviours (dog aggression, etc), but alot of the changes were unfortunatly not ones that the owner wanted”(wolfsoul).
I have little experience with female dogs but that might be something you would want to look into. Most aggressive behavior is related to testosterone, it stimulates the aggressive part of the brain. It could be that your dog has an estrogen deficiency or an abnormally high testosterone level for a female. Which if you cut out the estrogen source would explain why this has been seen as negative in some females. I’m sure your vet can test their hormone levels just to be sure before the surgery. The solution could be as simple as an estrogen supplement.
Usually this kind of behavior is derived from the dog wanting to be the alpha, but it sounds very apparent that you are the leader. This makes the scenario all the more unusual. Because of the odd circumstances you might want to check out any kind of possibility, not just the seemingly obvious. If I thought you were just a normal pet owner I would recommend the spaying, but since you obviously aren’t and you clearly have plenty of experience you should probably investigate it further.