Hi-we got our adorable english bulldog, Buck, a year ago. He was 10 months old. The prior owners simply said they could not afford his upkeep in this current economy. He has followed one of us from room 2 room from day 1. He needs 2 be w/people. We like this. He is typically very sweet, friendly, & loving. Recently he began growling, nipping, & acting like he would bite if he could to not only strangers but 2 us (me, my husband, & our 2 daughters). It seems with us, it is when we r trying 2 remove him from car or furniture. With strangers he appears frightened now & tries 2 bite when they reach 2 pet him. He is not neutered. We have not had any unusual changes other than his food. A small boy recently was looking at him & when he reached 2 pet Buck-the dog lunged him aggressively. He snapped a couple of times in the air. He acts frightened but we all give him nothing but love & attention. Vet says he is healthy. Brand new 2 your site. I am about 2 download resources. I know that will be helpful but could not wait 2 get feedback. We have had 2 other bullies that were super good natured. Thank u for any advice! I do not want 2 get rid of dog we all love but I can't have a dog around children that could unpredictably bite. My guess is we as owners r the problem. We r beginning our training today!
It sounds like your dog is starting to show a bit of dominance problems - it could be that coming into your house, Buck assumed he was higher than actually is in the family hierarchy, and it was somewhat reinforced if your family didnt correct things like getting on furniture by his own decision. So now, when you go to move him, he reacts aggressively.
Stop letting him on furniture for a while. Absolutely no getting up. With the car, he only gets in AFTER you've told him to get in - don't let him in on his own accord, so to speak. He needs to learn that these places are priveleges, so he doesnt get access without your permission. Once he's calmed down a bit, you can let him on furniture, but only when you invite him up - not otherwise.
If you go to move him from somewhere in the house and he growls, put him in time out immediately. Leave him on his own for about 10 minutes, then bring him out again. Any time he shows aggressive behaviour, do this.
He should learn pretty quickly that resources, including time with you, will be removed if he behaves poorly. I hope the Secrets to Dog Training helps as well - please let us know how things are going!