Sorry, I’ve had more important things to dwell on than animal restraints.
I have no idea what an “invisible fence” looks like or how well it works. Cops are under no more obligation to allow themselves to be chewed upon than regular people.
Get your head out of the sand and join modern America.
Cops have no business on anyone’s private property unless the property owner summoned them or they have a warrant signed by a judge,
PERIOD
BTW, what if Barney Fife missed the dog and the bullet hit one of the kids inside the house?