If you walk your dog in a designated green space, it is polite to pick up their waste and dispose of it in a trash receptacle. Some homeowner associations, parks, or apartment complexes will even provide the trash receptacle and bio degradable bags. Biodegradable bags do not simply mean that you should throw your pet waste in a natural area for nature to take care of it. Believe it or not it is very common for people that are inconsiderate to throw pet waste bags directly into the water at a pond/lake when no one is looking. In addition to making unsanitary conditions for your neighbors, the neighborhood kids, and professionals maintaining your pond/lake, it rapidly adds nutrients to the pond which can lead to algae and nuisance vegetation growth.
Make receptacles and bags available, and maintain them. Use signage to give instructions and raise awareness.
We all love animals. Animals make waste. Properly dispose of it.