English Bull Dog aggression

I have a 4year old English bulldog who starting at about 2years started showing some aggression infrequently. Now I'm frightened to take him outside because he goes after other dogs and people, not everyone but definetly more frequent than ever before. He was well socialized as a puppy, never had a problem until he started getting older. At about the same time he stopped walking with just one person, will only go if at least two ppl are there. He is the biggest sweet heart when he's with his family, but now I am scared to introduce him to any dog or person, because sometimes he goes after them.

I have ordered a muzzle so I can take him out and try to correct his aggressive behavior without being concerned about him hurting someone else, but if anyone has any insight into why or other ways to help correct his bad behavior I would appreciate it!

Has he been neutered? Sometimes behavioral changes are hormonal, if not. I would immediately start retraining him, walking him on a short leash, and working on basic obedience with him. You might see if there's any classes available that might help you retrain yourself and him. Right now, it sounds like he is in charge, and you are afraid of what will happen, and so that needs to change. Dogs will pick up on any uncertainty on your part, and take advantage. Start back at the beginning, where he has to earn any praise or treats. I hope this will help.

Being a bully breed, dog aggression is to be expected as they mature. I don't know if a muzzle would be a good idea or not.. especially for an English Bulldog. Just don't let him around other dogs, don't take him to the dog park, etc. If you have other dogs, I suggest you keep them seperate. I have met many DA English Bulldogs. Bully breeds like to be with their people, not so much other dogs.