A: I worm my dogs monthly with Sentinel and 3 times a year, they all get a round of Panacur, just in case.
B: I have no children and no personal inclination to ‘sample’ their droppings, myself which is how a few children end up infested.
[of course, if parents would bother to watch their kids, they would probably dissuade them from eating dog or cat crap]
C: Very few canid parasites can cross the species barrier.
You have a phobia.
Stop trying to infect other people with it.
Oddly enough, the internal parasites that *most* people have do NOT come from their pets.
In third world countries with little or no sanitation, the people are infested with all sorts of exotic creepy-crawlies.
My advice to you is NEVER travel overseas and if you do, -don’t- drink the water.
Here’s a list guaranteed to give you nightmares:
http://en.wikipedia.org/wiki/List_of_parasites_(human)
NOBODY is ever truly safe from parasitic infestation, having pets or not.
Sweet dreams.