Dog feces in backyard is a call for the department of sanitation?

You've got a really nosey neighbor. It's true that dog feces can draw the attention of many flies and flies do carry disease. I think each City has different laws with regard to animals. I would call the Humane Society and/or Animal Control and the City of_________, that's where you'll find leash laws and zoning laws, etc. I don't think they can do much about you leaving one pile in the back yard, but for your dogs sake, you should clean it up, immediately. I am a breeder of tiny dogs, I use wee pads and a 2 huge litter boxes. I clean up whatever they do immediately...even urine. I do this because of the flies and because it's the sanitary thing to do. Dogs get sick from all kinds of things outside. It's good that you walk your dog in the backyard, because that means you can see the droppings immediately. I believe in being a responsible dog owner, both for the dogs sake and your neighbor's sake. I hope this helps in some way. Good luck with the neighbor.