Reading a lot of these posts has me realizing that I am probably more tolerant of inconveniences than others. When I come to Disney, or anywhere for that matter, I do not have my rose-colored glasses on. I realize I'm not going to have perfect campers next to me on every trip, not everyone is going to follow the rules, some of the kids are going to yell and scream more than I would like to hear it, a car is going to drive too fast through the loop, a golf cart is going to be driven with an under-aged kid at the wheel or drive the wrong way in the loop, there will be loud drunks at the next sites, etc. you get my meaning. Whether these are "rules" or just an "occasional annoyances", they are going to happen. I'm not going to waste my vacation time by being " 'permanent fixtures' at the Outpost until the issue was taken care of!!" (quoting another poster.) I don't come to WDW expecting Disney to give me a "near perfect experience" because you can't control what all of the thousands of other people are doing.
If I were in the OP's situation and I had requested a non-pet loop then I would have made sure I was not in a pet loop. I would have researched ahead of time which Premium loops were designated as non-pet loops so that when they assigned me the 400 loop, I would have know it was pet friendly. Possibly his request got lost or overlooked. I'm sure they would have had a site available in the 1000 through 1400 loop which are designated non-pet. Granted there is always the possibility that there will be a pet in one of those loops but you stand a better chance that there will be less pets. You also stand a better chance getting a dog problem resolved if you are in a non-pet loop. If all my attempts to get a non-pet site fail, then I make the best of it -- after all, I'm at Disney. You can tell by the previous posts who likes (or has dogs) and who doesn't because if you have pets you tend to be more tolerant because you realize stuff like this will happen. However, today more and more people are traveling with pets so it's more common to have a pet camping close to you.
Also if I checked into a site that had a lot of dog poop in it, I would immediately call the front desk to get someone out there to clean it up. Obviously the previous camper on that site was not a considerate pet owner. Hey, it happens so you either clean it up yourself, call maintenance or request another site.
Just my thoughts!!!!