You're walking outside and you see a dog that's not yours attacking a person, how would you get the dog off of them?

[Anonymous]

Throw a shoe or something at the dog

If I have pepper spray

Yell as loud as I can at it

I wouldn't know what to do

Carefully use something I have on me (phone, keys) to distract it

[Effably]

Well these are not very good options.

In reality your choices are to calm it down, scare it or subdue it. If you have an implement it depends on that, otherwise the most reliable way for a human to win a physical contedt against a canine, or feline, is to get their back and control their head.

That said, I much prefer dogs to people and am willing to assume the dog is probably in the right here.

[contentious]

I had a dog attack me once. I just sternly said, "Heh! cut it out..." and it instantly released it's bite and walked away in fear knowing that I was serious and what came next. Had it not listened to my warning it would be dead.

[contentious]

Dogs have a certain mentality. If they attack an animal, they expect it to flee in fear which triggers their prey drive and promotes their continued attack. They are hunters. They get blood lust and carry on the attack more rapidly. If they attack a bigger animal that has no fear which stands it's ground they realize they just fucked up and they should retreat before they get hurt.

Worse yet for the dog that attacked me once it realized it was the weaker dog in the fight, provoked aggression from two other dogs for fucking up and those dogs attacked him to defend me. He was out of line and the other dogs put him in his place for messing with the big dog (me).

[Nikki1989]

Yell and firmly, clap your hands loudly, or make another sharp, sudden noise to momentarily startle or distract the dog.

[DryGermanGuy]

Depending on the dog, this might be almost impossible, short of shooting it. A dog owner I knew told me he would kick an attacking dog in the ribcage as hard as he could.

[Staximus]

Kill the dog