Wow, that's sad -- medicating pets with OTC medications seems at best, foolhardy, and at worst, deadly.
We have a yappy and uncontrolled dog next door to us that frequently gets out. Everyone in the neighborhood knows its name because one hears it yelled at
least once per day as the owners try to track it down. It's a tiny dog and has already had one broken leg.
We have three indoor-only cats. Everytime I think a dog would be a great pet, I look at the size of my backyard (tiny, but filled with birdfeeders and a nice deck) and my schedule and know we wouldn't be a good home for a pup, much less a fully grown adult dog.
All of my bad experiences hiking or camping have been exclusively with people, thus far, not pets. However, it's safe to say if the people are noisy, discourteous or prone to polluting their pets will cause similar problems. Folks who don't cause those problems keep their pets from doing the same, or take swift action (such as cleaning up after them) after the fact.