Mary have Michael to get you a .22 mag, it shoots like a .22LR, but travels faster and hits harder, uses hollow points, it will drop a pit bull at 200 yards easy, get a simple scope with it and practice, you will get very good with it.
Then, SSS.
You have warned them, that is more then enough. You have to protect yours. No one can afford to lose grandchildren. Or your own critters. I had a .22 mag may get another, or .243 Win. Until then I have a .22, a .45 auto, and a 30-30, no dogs allowed that I dont know and welcome.
You might consider a pyr or maremma like Michelles, they get the job done, big time and are great with granduns. Its just the time element involved in their growing up, but you are all set next year.
In the meantime, get the .22 mag.
I had a great day yesterday, visited my goats, I have two Alpine/Saanen wethers, April born, one Boer/Apine wether to be, also april, one Saanen doe, March born,one Alpine doe. also March, and one Boer/Kiko doe May born. Sat in the pen, feeding treats, keeping them off my lap, rubbing them down, one big family, having fun. In the spring I am getting a Kiko buckling to breed to all of them to see what size packgoats we can raise up, and have the home milk, and cheese plus feeding the kids. All of them are totally used to chickens they even let chickens eat along with them, just part of their world.Where they are is one of the folks starting a flock of Icelandics and so they even know what Icelandics are.
I am getting a dog, an English Shepherd, great farm watchdogs, he is used to both sheep and chickens, and people, I had planned on picking him up this summer but instead will pick him up on the way west, and we will get to know one another on the trip. He is a son of a female I gave to the breeder, so I know his lines well. He is just over 2 years of age, he'll be getting to know the goats on the trip when I unload them for tie outs to feed them a bit of grain.
Life is good, and better with Icelandics.