I have had male Labs for a long time, only one female a long time ago. A couple of my males, when they reached around 1 year, growled when being disciplined. In both cases I grabbed them and flipped them over on their back, and bit them hard in the throat while growling myself. Hard enough that I spit out hair. Neither of those ever growled again while being disciplined.

A recent male, however, was just strange. It was to the point I believed there were underlying issues beyond standard training...in essence mentally ill. One evening as I was on my way home from work I got a call from my wife. To make a long story short, she had been nicely petting him in the kitchen when his hair went up and he began growling at her. She is disabled and backed off and he advanced while growling. No rhyme, reason, or cause for his behavior. Got home, kept him locked in the litchen, and took him for a one-way trip to the Vet the next morning.

The reason I tell that story is that I firmly believe there are dogs in this world that exhibit behaviors that cannot be trained out. Biting is a tough one to even try to deal with. There may be some underlying causes for your dog to be acting that way that are beyond her and beyond you to change.

Best of luck to you and your family in this.

Moosetrot

It's genetic. There is no cure.
You can tightly monitor ALL interactions... until the dog goes too far and must be put down. Or put her down now.
Sucks big time, but in my experience that's just how it is.

At 18 months you're probably past any guarantee or return policy with the breeder.

Vet should check thyroid levels

Thanks everyone. Yes, these aggressions have been totally unprovoked and started at the MTA convention with a member on here. If the kids were pulling her tail or something I kind of get it but it isn't like that. She is a BEAUTIFUL do that we paid a lot of money for, she is a great dog to us, fantastic nose, etc but no amount of that can make up for being aggressive towards a kid and I am not willing to take that chance. I guess deep down I knew what the answer was and was just hoping for a "miracle". It's the boys dog so obviously he is pretty bummed and doesn't fully understand "why" his dog needs to be taken away.

"By dicipline do you mean beat? If thats the case i would growl too."

No, ccl...I do not beat my dogs.

Moosetrot

No body at least not normal people, likes shooting a dog. Be something wrong with you if you did . Its lots worse to haul a kid to the er. Because you did not