The Dogs Make Us Crazy

Well our two dogs that average less than 8 pounds are just nuts!
They are precious, but when we go out for a walk, always on leash, they have progressively been more aggressive, over time. When we first arrived at our RV site, the boys were cautious and merely growled at other dogs who were in the area (usually close to home). Now they (mainly JJ) go into attack mode whenever they see another dog, no matter how large. (JJ says RAWF!, RAWF!, and Grover says ruwf, ruwf very quietly) Recently, however, JJ has decided that he as every much as big and tough as the largest dawg on property.
So far this has been irritating to us and other dog owners, but also we have concerns that he may charge another dog who may decide that JJ is just another lunch.
Today, for example, JJ really got aggressive. When I pulled him back he slipped out of his collar and charged the other dog (who happened to be a 75-lb yellow something-or-other named Maxie who is owned by the RV park owners) and nipped the poor girl on the butt twice. The object of the attack was very frightened, and after I yelled at JJ he was also. After apologies, and appropriate chastisement we continued on our walk.
So, I think we will be more attentive to our dogs' attitudes and perhaps begin a new training program. Erck! We don't like misbehaving "children."