Karl Townsend writes:

Anyway, I've heard of filling a 12 gauge shell with rock salt from the
water softener.

If using a firearm against a neighbor's pets if unlawful in your
jurisdiction, the particular load you choose will not in the least excuse
your crime. It is one thing to shoot varmints, and another to shoot
"members of the household", as some people consider their pets.

A local schoolgirl was mauled by a pair of pit bulls running loose last
week. The responding deputy took out the dogs with his sidearm, and he
still got grief for it, although he was presumably within the law.