I spit on the ground when I was running by
What did you do that for?
Someone left their dog's shit on the ground.
Although it is disgusting when someone doesn't pick up after their dog, spitting on the ground just further makes the ground even dirtier. In the future, you should just move on and put it out of your mind instead of spitting.
People do hate shit and spit. If someone already dirtied the area with dog shit, then I'm just gonna spit since it's not doing any harm.
Maybe you can find the owner next time and let them know they need to pick it up. They may also have an app that you can use to report where you find dog poop so other people can avoid it.