If you are walking with your dog, you will be glad to have snake shot loaded in your revolver.
The dog will attack (at least mine do). Granted, my dogs have never been well trained hunting dogs ... and maybe some folks have dogs that will obediently step back and ignore the snake. Mine never do.
I had a beagle that was bit on her muzzle on three occassions. She would alert us to the snake in the back yard by barking at a safe distance. Once we came out to see what the noise was, she would go into "protect mode" and attack the snake. The closer I got to the snake (with a hoe), the more aggressive she got. A quick shot at a little distance may have saved her some pain and a lot of swelling.
When going out into potential snake territory, I take along shot shell for my Ruger Blackhawk. Its a lot easier to hit snakes with the shot than with a single bullet.
I went camping two years ago with my son. His dog alerted us to a large rattler around dusk. Neither of us could see the snake very well. We unloaded shotguns and pistols into the general area of the snake. Not being able to see into the darkness, we decided to leave the campground for a while and drove into town for supper. We wanted to give the snake a chance to either crawl away or die.
The next morning we checked on the snake, who was dead ... and about 6 1/2 feet long. Not sure what killed it, but glad we had some weapons with scatter.
Never argue with drunks or crazy people.