Do you pick up dogs poo?

I always pick up after my dogs. We keep our backyard picked up as well. If my dog went off trail in the woods...no I wouldn't be picking it up.
I have had people who expected me to pick up my horses poo though...while riding her. There is a trail here that goes from one end of Portland clear out into out-lying country towns, the section I ride my horse on is asphalt in the center and hog fuel on the sides, it is out in the country...I ride off to the side for the most part just in case she does leave some fertilizer behind. I have had joggers or bikers make comments to me about their dislike of horses on the trail. I won't repeat my response to them here, suffice it to say that the trail is for ALL to enjoy and out there many many people trail ride it. Not all keep their horses to the side as I do...but anyone who has been around horses knows that horse poo is not like dog poo at all...it's mostly hay and disappears quickly. If you step in it, it kicks off easily. The area has recently had a few expensive housing developements go up right smack in the middle of farm country, city people move out there and then have a fit when the country gets in their way. I just think you have to stop and consider your surroundings...if you are jogging out in the boonies on a trail you know is dominated by horse riders and has been for many years...and you are the new guy...best to take off the walkman headset so you don't run yourself up the back end of a horse and be prepared to dodge some "haystacks".