I think I would've called the sheriff after shooting the dog to have the owner reported. Actually, I don't carry a gun, but would if I thought loose Pit Bulls were a possibility on my rivers. Dogs like that don't belong on public property off-leash. Grown men have been killed or badly injured in similar circumstances. What if you had a child with you?

BTW, Veterinarians love to have clients who fish take their dogs with them. It's good for business! Swallowed fish hooks, salmon poisoning, porcupine quills, foxtails, giardia, lacerations, etc. Sorry, just a veterinarians joke. Still waiting for my annual salmon poisoning case this year.