Lack of fencing/secure enclosures seems to be a pretty common!
This thread is just one small example, people on this forum are always posting that dogs or other predators (including their family dogs) managed to hurt or kill their chicks/chickens and 99% of the time they did NOT have fencing or other basic security measures in place.
True enough, around here I often see range hens in the ditches near a major highway. I personally love grilled chicken, but not like that. lol
It's just that a few commenters have made it seem like those with firearms don't have fencing at all. Maybe I'm reading more into those comments than I should.

My situation, for example; I do have a firearm, and I would have no qualms about shooting a dog (coyote, raccoon, what have you) that gets past my fencing and harasses my flock. Does it mean my fencing is crap? Not necessarily. It's not Fort Knox but it's secure and, knock on wood, I have had no issues with predators in the past several years since I started working with much more valuable birds and did in fact invest into a higher level of containment.
Having said that, I have seen cases of some very desperate domestic dogs tear through secure fencing to get at the creamy center inside. In this case what should one do... stand around, watching the dog eating their beloved flock while they contemplate putting up more secure fencing?
Should they run out there and attempt to manhandle the strange dog and get it off their flock while its being overly playful or flat out aggressive and risk turning into the new plaything for said dog?
Should they run out there swinging a bat, possibly hitting the dog and breaking its spine, leg, etc to let it scream and wimper in pain?
Those may be options for some. But I personally prefer having a firearm as a quick and humane way to end any additional losses of my stock while keeping myself safe from an unknown dog/dogs. I don't and would never enjoy killing a dog. But you can bet your boots I will do what I can as quickly as possible to end the casualties in my flock.