Answer:
These signs are often seen around cities or popular public areas. "Curb your dog" means that owners must keep their dogs from soiling buildings, sidewalks, public parks and walkways.
Dog owners in urban areas should refrain from letting their dogs go to the bathroom in the middle of a sidewalk or urinating on the side of a building. Responsible owners take their dog to the curb teaching their dogs to go to the bathroom in the proper location.