A friend of mine recently took in her first foster, a miniature poodle relinquished to Whipstaff Ranch after a local breeding facility decided to "liquidate its stock."
The good news is: The majority of the 1,200 dogs and puppies reportedly at the facility have been safely placed into rescue groups that will medically treat, socialize, and place them in loving homes. And happily, these dogs are less fearful than most of the puppy mill dogs I've worked with.
Still, like all mill dogs (and shy-fearfuls), they create training challenges. Gracie, my friend's foster, didn't know how to walk up stairs, had not been potty trained, didn't vocalize, didn't play, and my friend bemoaned, "Will she ever be normal?" Well, that presumes a "normal" set of dog behaviors exists, but although Gracie may never be as confident as some dogs that have been loved and cared for all their lives, her prognosis is promising.
The first step is to start training her and to push her outside of her comfort zone a bit. That doesn't mean it is wise--or even responsible--to throw her on a leash and take her out for a walk. Many a well-meaning rescuer has done just that and ended up with a loose, undersocialized dog, a very dangerous situation for the dog with low odds of a good outcome. In fact, these dogs can be so fearful that they can even get loose from fenced yards or lost in them when they panic.
Start slowly. Rather than throwing a potentially traumatized dog on a leash outside (which it may have never experienced), attach a leash on her collar when you are home and can superverise to make sure she doesn't get tangled up and hurt herself. Let her drag the leash for a half an hour or so. After the dog becomes comfortable with the leash attached to her collar, pick up the other end of the leash from time-to-time to desensitize her a bit. Generally increase the amount of time you walk her on leash inside before venture outside into unsecured areas.
To take this approach a step further, try "umbilical training," during which you attach the dog's leash to yourself for an extended period of time, usually a couple of days. Umbilical training is highly regarded by many rescue people I've met, and we use it to help build confidence in undersocialized dogs, to help unfocused dogs connect, and to aide with potty training. I've used it myself with terrific results.
Remember, though, that mill and shy-fearful dogs are easily intimidated. Add time and activities gradually, as they become more confident, but don't coddle them so much that they don't have any motivation to come out of their shells.
So, why not try it? Let your mill or shy-fearful dog drag the leash while you supervise, and work up to umbilical training.
And good luck, Gracie!