Had a "Fido calling card" left on our site this week. I was stewing about it, yet glad I hadn't stepped in it, as I am often in bare feet in the grass.
I opened the rv garage hatch, grabbed the kid-sized shovel I keep hanging there, and tossed it into the weeds.
DW saw neighbors put their heads down and look away. Later we saw they had a young child who walks the dog.
Either way, we didn't have a repeat. Although it irked me, it didn't kill me. We decided to go ahead and have fun and leave the grumpiness in the weeds with the other crap.
I do understand why places have pet free sites/areas.