We have had the problem around here, with dog packs running sheep and other farm animals, moose and deer. They have also attacked children and hikers, so this is far from a remote possibility. The larger breeds also X-breed with coyotes and wolves. The carnage left behind can be awful.
In Alaska and other less sentimental places, a loose dog is a dead dog, particularly in winter. Sorry. I love my dogs, too. But a loose 100lb dog running in a pack with others is a dangerous wild animal.
There is no evidence that the two mastiffs had joined a pack of strays; these mastiffs were defending their property FROM a stray that was establishing that their yard was *his* territory.
Cogent response Kenny. I was chief in a small town 1/10th the size of the town I retired from. We had more dog calls in a month than my former agency had in a year. Small towns let their dogs run loose and think nothing of it. I bought those nooses on poles so we could snag them instead of shooting them. Most dogs comply pretty quick when they get snagged. This worked where I was at because of the size of agency and we didn’t have all the electronic stuff in the trunk.