I live in town, so there's no way a gun could be fired at the dog. I couldn't shoot and kill a dog anyway, unless it was attacking my human children. I am first and foremost an animal lover of most all species. Dogs and cats being #1 and #2, just not real sure of what order, guess it depends on what day it is, and who has behaved best on such day. Chickens are new to me, and I am quite surprised that they have their own personalities...just like dogs and cats..who would've thunk it? Anyhow, my chicken kids are becoming quite important to me, and I just want to do my best to keep them safe and happy. We have built a new fence with a sturdy gate. The chickens have a brand new predator proof coop..which they don't like. They prefer their little rickety tractor coop that they grew up in and was given to me when I adopted them. I let them stay in their little coop, and have made sure they have access to the big sturdy coop too. There's no way a dog could get into it. We plan on building the girls another tractor very similar to the rickety one..except much sturdier. My husband wants to purchase a big heavy duty dog pen to put inside the fence, so the chickens would have 2 layers of defense.
I am in a similar situation to you, I live outside the city limits, but only by a mile and a half. My neighbors are close enough that if I fired a gun I could hit them from ricochet. There is a man up the street who feeds every loose dog and just recently stole a purebred Siberian husky, luckily for the Siberian people called me (as I breed and raise show Siberians and agility Siberians).The original owners had put up flyers and we were able to get him back home. The owners told us how the dog got loose, with owners in pursuit, and then a black SUV pulled up and grab the dog. They lost the SUV in traffic but got close enough to flyer our neighborhood. The thief doesn't take care of the dogs he has, yet steals more? It's mind blowing! This mans loose dogs (at last count 10-12, and running in 2 packs) have menaced my animals many times, last year they even cornered my outside cat (who is a great mouser) and tried to kill her. I beat the dang dogs with a baseball bat (it was the only thing I could get to once I realized what the racket was all about) to save Ms. Patches, she was surrounded by 4 dogs on my property. I have heard the dogs did bite a15 year old boy walking home from school, so I consider them dangerous dogs. I have reinforced my fencing, am training my rescued Belgian Malinois as a chicken, duck, goose protector, and I brought rat shot for my 9mm handgun (it doesn't pack as much punch, so less danger of hitting neighbors property, and still deadly at the right distance). No animal control will come here, and the sheriff says to shoot any threatening dog on my property and report it. I prefer not to kill dogs as I love them, but I will to protect my children, flock, dogs, and myself. So far, the loose dogs have not dared to come back after the beating I gave them last year for attacking Patches, but it's only a matter of time.
As I previously said I raise Siberian huskies, they are escape artists and have a very high prey drive. None of my dogs has ever gotten loose, and they live side by side with my flock, the dogs can see and smell the chickens every day. Containing a dog isn't hard, or even expensive, but it is a dog owners responsibility. I have multiple layers of protection around my flock, because most people don't care about their dogs, and care even less about damages their dogs cause others.
Good luck, I hope your chicken is ok.