I doubt that coming in contact with dog feces one time would expose you to much.
I would take extra garlic capsules and/or raw garlic 4 or 5 times spread throughout the day, for a couple of days, its a natural killer of germs in the system. if your immune system if good, it should throw anything thats bad off.
The spices that you are taking kill germs too. Fresh lemon juice diluted in pure water is good as well.