^^^what "themacpack" said.
There is nothing worse than domestic-dogs-gone-wild packing up against livestock. Especially when the dogs have been dumped and need food.
I am in my 60's and can remember, as a child, all the farmers gathering on a Saturday to go wild dog hunting, if there had been a rash of cow and/or calf killings.
Dogs WILL bring down a 2,000 lb cow in heartbeat. The cow cannot outrun them and once those dogs get a taste for blood and the sport of killing (along with fresh red meat) there's nothing left to do but hunt the dogs down and send them onto their ancestors. A bullet in the head by a sharpshooter farmer is much less painful than getting hit by a car in the middle of the night.