In our 15+ years of traveling, we've only had one occasion when we were parked beside a MH with two yappy dogs who barked almost constantly when their owners were gone.
we've seen quite a bit more of the not picking up after pooping action, but it isn't worth making a mountain out of a mole hill. just one of the many, small annoyances of life :)
when you are walking your cat, keep a sharp eye out for the rare dog whose owner feels like it is an insult to his mastery over the dog..to keep it on a leash.