Stefanie emailed this question...
Just after Christmas, I adopted a blue heeler mix from a rescue group. She is approximately 4 years old. I took her to the vet and since I live in the desert - had them run a full desert blood panel on her. All results came back negative. Her white blood cell count was slightly elevated, but I was told that may be due to allergies or the tail end of a parasite she may have been fighting. She will be retested in a couple of months to see if that has improved. The only other health issue that was revealed by x-rays was hip dysplasia and she is currently on Phycox to manage that.
I have only had her a few weeks, so I realize that I will continue to notice new things about her as her personality unfolds. Just last night though, she became nervous and fearful of shadows on the wall. And then this morning, she saw my reflection in a window and that made her run back inside of the house. I called her outside again and she did her business and seemed ok. I just avoided walking in front of that particular window. It's hard to say what kinds of experiences she may have had in her previous home - but I was wondering if this is one of those things that will just fade away or if there is a serious neurological reason that this has started to occur? Please keep in mind, I don't coddle her when she fears something - I go about normal business and use a happy voice so I don't reinforce her fearful behavior. There haven't been any other changes as far as her house training, eating, drinking - all of those continue to be normal. She does sleep a lot - but again, she's only been with me a few weeks and I'm thinking that the walks/hikes are contributing to that and as she becomes used to the exercise - she'll be more active.
Some dogs are just scaredy-cats (irony intended), and it may have nothing to do with previous abuse. One of my dogs, a very sweet young yellow lab, is like this. A flock of birds suddenly flying from the trees can send her running back to the porch with her tail between her legs. Just last night we came home from theater rehearsal and I deliberately hid in the darkness inside when my wife let her out, just so I would scare her a little and get her to bark. She did bark, jumped back a little, then relaxed when she saw who it was.
I share this about my dog to show how some pets can have this kind of personality. We picked out my dog when she was less than two weeks old and took her home at around 6-7 weeks old, so I know she hasn't been abused (quite the opposite...she is very spoiled by my wife). Stefanine, in your case we probably will never know what kind of life your dog had over the last four years, and it is possible that she was abused and now is scared of relatively simple things such as shadows and reflections. However, it is just as likely that this is simply her personality. Many behaviors do begin with a trigger, and something in her past may have caused her to be jumpy at indistinct shapes. But regardless as to whether or not there is a causitive factor, you still have the current behavior to deal with.
I would first talk to your vet about her vision. If there is any question whatsoever, you may consider having an ophthalmology specialist evaluate her. Sometimes vision problems can be subtle, and if she has any deficits in her sight it can cause her to have difficulty telling what is a shadow and what is real. Unfortunately a dog cannot tell us what they see, so it can sometimes take specialized knowledge and equipment to assess her vision in detail.
If everything is fine with her physically, continue to praise and reward calm behavior. When she sees shadows but doesn't react, give her good attention and a small treat. An adage I use frequently is "behavior that gets rewarded gets repeated", so reward the good behavior and try to ignore the bad. If she persists or worsens, you may want to talk to your vet about various antianxiety treatments, ranging from Dog Appeasing Phereomone (D.A.P.) to Thunder Shirts (not just for storms), and even prescription medications. Since your vet knows your dog better than I do, and can see her in the clinic, they are better positioned to help determine the cause and treatment.