I grew up as a paperboy in Honolulu for 3 years. 4:30~5:30AM riding my bike delivering papers in the dark. We used to carry penny sticks to ward off the evil things. Take $1.50 in penny rolls (3) and tape them together with black electricians tape. Made a flexible and nasty piece and set you back all of $2 including the tape.
Riding around in the dark and working around the dogs, you get a pretty decent idea about their intentions. The only time I did get nailed, a doberman leapt from behind a hedge as I rode up and knocked me from the bike. 100% blind sided me. Absolutely no warning. No bark. Just a blur out of the corner of my eye and whomp! I was flying. Seeing as I was all of 11, the dog probably outweighed me. Once I stopped riding and I was down, the dogged came up and sniffed me. Gave me a "huff" and walked away. I guess he just didn't like my bike riding techniques! I saw him again and he never took interest in me after that. I must have been a game he wanted to try out.
Anyway, it seems like you have major dog issues and need to learn to analyze things a little better. You were in the car. You were 100% protected. You controlled the situation. When you draw the gun, you were no longer in control of the situation. The situation has gotten so out of control you felt that you would need to terminate a life to regain that control. You could have stayed in the car. You could have opened the window and spoken to the dog to gauge it's reaction. It's not like it has the ability to rip open the door and pull you out. Time was on your side, as was a higher IQ (hopefully
) and opposable thumbs. Having to get inside and take a pee doesn't justify killing a dog so you can get to your front door and use the restroom. It's not a matter of letting the dog get the better of you, it's a matter of being better then the dog.
It would be extremely difficult for me to sit on a jury of self defense case and try to 2nd guess why someone had to kill another to save their life or defend someone else. I would not want to have to 2nd guess at what point the situation reached the point that this was necessary. The one time I was on a jury for a three strikes criminal, I was the lone juror who drew the deliberations out from the 3 hours the others wanted to give the the case, to 3 days. Trying to put myself in the shoes of the person on the stand to see what was happening at the time wasn't cut and dry and when you're in a position to have a major impact on another persons life, passing judgment is pretty weighty. That being said, nothing in your story suggests you ever reached that point and if you were in front of a jury regarding this situation, I would find against you.
I'm also curious what laws you might have been charged with had you discharged your firearm in a residential area and killed your neighbors dog. Reckless endangerment? Illegal discharge of a firearm in city limits? Just wondering. I have no idea. I would assume you'd get hit pretty hard civilly too.