Labs are toooo friendly, they love everyone, they just don't get that everyone doesn't love them. I try my best to prevent Cadbury from 'rushing' dogs, doesn't always work but I am learning this is more due to me than him (I lack confidence, as my trainer explains, and this comes across when Cadbury is off lead). But I am working on it and we are making progress. Some lab owners don't think its a problem, I do and I aim to have dog that will respond to me and not run up to any dog it pleases.
However, there are also those people, as someone else mentioned, that don't get that their dogs are aggressive, and enable their behaviour to continue which then can impact on other dogs.
When I joined my Beginners class I was with four terriers. The first day I walked through the door, Cadbury had barely set down a paw and every dog set off on him led by this particular black dog.
Cadbury is thankfully very submissive - apparently this is unusual for a lab. So over time most of them were amicable with him - not the black terrier. One session we were going to be practicing socialising. All dogs were on lead and we were walking around. A cairn terrier approached Cadbury who rolled straight on his back as he is a bit scared of terriers (had his nose bitten at 4 months while he was on lead, sitting by my side, by a JRT on a flex-lead

). This meeting was going OK, until the black terrier approached. She realised Cadbury was submitting and decided to attack and then suddenly another terrier appeared and joined in. Thankfully there was no biting, but they were all terrorising Cadbury. My trainer stormed over (she can be scary!). She wanted to know why the terrier owners had enabled their dogs to gang up on Cadbury when he was defenseless because he was on his back. She said they had ganged up on him because he was vulnerable and that the other owners should never have allowed them to do that. She also made it a point of saying it wasn't Cadbury's fault, which made me feel better (I always think I've done something wrong!)
We moved on to off lead recalls. The trainer took me aside and explained she was going to bring in her dog during the exercise because she knew the black terrier was liable to cause a scene. She has a Leonberger (now that's a big dog), well he was a genuine Alpha dog, aloof, confident, wonderful.
The off lead stuff begins, she introduced the dogs gradually, mostly it was OK. Cadbury tried to appease the terriers by giving them toys. Then the black terrier was introduced - well I've never seen anything like it! She raced across the ground, jumped at the Leonbergers face and bit his nose. To his credit the Leonberger ignored her completely. The black terrier kept attacking the trainer's dog. The owner just stood there.
My trainer was flabberghasted, "you do know your dog is attacking?" she asked the owner - the owner thought she was playing
Sorry for rambling, I guess that was a story I needed to get off my chest, it really bugged me at the time because these owners would allow their black terrier to come up to Cadbury in the car park prior to every training class to 'socialise' and this would result in Cadbury's nose being nipped even when he was laying on his back in submission.
I came to really hate that dog.
I hope you can help your dog - do you have a friend with a really placid, submissive dog you could work with? I'd offer Cadbury, he gets used as a stooge with fearful dogs quite often because he is so submissive, but I would have to charge you air fare

