If you insist on walking or riding your dog, cat, horse, hamster, etc. on trails which you should not be on in the first place, at least have the common courtesy to clean up after it.
My wife and I managed to pick up a considerable amount of dog crap on Kickapoo Down tonight whilst finishing off a most excellent ride at Sunderbruch Park. The crap was in a very inopportune spot, just around the last hairpin corner and largely unavoidable. I couldn't even tell what it was at first until I saw my front tire strobing on and off as we coasted back to the parking lot. The smell wafted up and I knew immediately what it was. Occam's Razor: If it looks like dog crap and smells like dog crap, it's probably dog crap.
I wasn't going to mention it because I feel it is a lost cause and I'm tired of concerning myself with it, but there was quite a bit of horse crap on Farmdale today when I walked up to take care of the weeds. I sighed and scooped it off the trail with my hoe and went on with my business. There are droppings right in the middle of the pavement up just beyond the dinosaur bones, and a large amount just after the bridge smashed down nicely.
So please, remember that your city parks are not sewage treatment plants or landfills or anything else where waste belongs. It is a park. It is for public recreational use, and wading through your animal's feces is not considered recreation. Your animal taking a dump in a public place is no more acceptable than you yourself taking a dump in a public place.
To quote jimithng23, STOP!