Actually, the reason I clean up after my dog has nothing to do with germs, disease, rules, or regulations. It has more to do with taking responsibility for my pet and being considerate of others.
I may be a bit old fashioned, but if I make a mess, I feel I'm responsible for cleaning it up. If I'm walking a dog and the dog makes a mess, then I feel I'm responsible for cleaning up that mess.
So if Tessa squats and poops in the middle of a trail, I'm going to clean up the mess because I don't want to inconvenience other folks sharing the trail. After reading all the other posts in this thread, I don't see why the same common courtesy wouldn't apply to folks riding horses on a trail they share with walkers, joggers, and bicycle riders.
So I guess my feeling is that if someone riding a horse is going to leave any "road apples" where they might fall, that person should probably stick to paths reserved exclusively for horses and stay away from paths shared with folks walking, jogging, or riding a bike.
I really appreciate the responses everyone has made to my original post - the letter I'll be sending to the park district is going to be a LOT more effective because of what I've read in this thread.
Have a GREAT day!
Rob