Absolutely. Dog waste contains bacteria and organisms that can spread disease in people and other dogs. In humans, contact with dog waste can cause stomach illnesses and rashes. Dog waste also spreads disease among dogs, including serious illnesses like giardia and parvovirus.
Dog waste also has environmental impacts. Unlike human waste, which is directed into sewage pipes, dog waste left on the ground eventually pollutes our waterways. Left on the ground, dog waste also deposits excessive amounts of nitrogen fertilizer to the soil, increasing the spread of nitrogen-loving weeds at the expense of native plants.