That doesn't look like 25 lbs a crap.
As far as what you could do, I don't mean to be a jerk here but you could try taking responsibility for your animal - a dog needs to have someone clean up after it.
But, if you really just want to **** with them, and you don't care about living there, simply get some latex gloves and smear the shit all over their vehicles, door knobs and under the door handles on the vehicles as well. You could also buy a large bag of laundry detergent and 'dump' it on their yard and then water it.
I'll try to be nice to you, if you stop being such an idiot