Dog turds are stealth weapons. People with 20/20 vision often fail to notice them until they appear hours later, on the bottom of a shoe. How the heck is someone who can't see supposed to track down and eliminate these sidewalk scourges, then?
First off, not everyone who is legally blind or has a guide dog is completely without vision. Some still have some vision and can pick up their dog's mess just fine.
Whether the dog's handler can see anything or not, you have to keep in mind that these dogs are pros. They guide their handlers through some very complex environments and make sure they don't fall over obstacles or walk into oncoming traffic. This, of course, requires a lot of training. And part of that training involves special bathroom etiquette.
When the dogs start their training as puppies, they're taught to associate a specific verbal command with the green light to go ahead and squat. The dogs only go on command. (These commands vary among trainers - some I've heard are "busy busy," "do your business" and "go time.") The dogs are also conditioned to not freak out when they get touched while doing their business.
With a well-trained dog, a blind handler can give the command to go, and pet the dog once it has found a spot and started to go. Dogs go into different stances depending on whether they're peeing or pooping, and by running a hand down the dog's back, the handler can figure out what's going on. If the dog's back is flat, it's peeing - male guide dogs are trained to not lift their leg when peeing; they utilize the same "lean forward" pee stances that females use - and no cleanup if needed. If the dog's back is rounded, handlers know some cleanup will be required. By feeling their way down the dog's back to its butt and tail, they have a pretty good idea of where the poop is going to wind up. Once the dog is finished, the handler just leans down with their plastic bag and can find the poop pretty easily.
Read the full text here: http://www.mentalfloss.com/blogs/archives/101168#ixzz20DkADAmF
--brought to you by mental_floss!