My dog is suddenly acting nervous/scared

Question
I have had my lab mix (fixed) for almost 3 years. We had adopted her from the local SPCA, she wasn't abused (to our knowledge) or anything. The owner claimed to have suddenly developed an allergy to her and put her up for adoption. She has a few weird habits that we obviously didn't teach her, like begging and jumping up on two legs when 'asked' to.

Anyway, in the last 4 days or so, she has been acting really strange. She has been getting nervous in the early mornings (6:00a.m till the sun is high in the sky) and late at night, around 7:00p.m. or so, generally after we feed her and take her on a walk. I don't understand why she is doing this, but she tucks her tail under her legs and constantly sniffs around. She tries to hide under me or someone else. She can't lay down, she'll just pace and tremble. Then all of a sudden, the weird behavior just stops until we all go upstairs to go to sleep, then she begins pacing and trying to hide under my bed (she sleeps in my room, but on the floor, not my bed).

We have been discussing what could be causing this behavior, too. For the past 4 days it's been really hot, and a cold front moved in from the west, which caused some loud and serious thunder storms (we were under tornado watch.) She is scared of thunder storms, and I normally try to comfort her, but since it's been over we have been getting this weird behavior from her. Second suspected cause is the thumps from my neighbor's house. Their noises only can be heard at night, when it's quiet, and I'll admit, sometimes it keeps me up for a while too. But their noises have been going on for a while now, before the dog even got spooked/scared. Third, we had assumed that the dog may be feeding off of my energy. I've been sort of nervous/scared/anxious lately myself, mainly because I've been watching alot of zombie movies so sometimes I get spooked when I hear a certain noise (at night) also. This was only temporary fear, and it has worn off within the past few weeks, so I don't really understand how this could be affecting her. Our fourth and final reason she may be acting like this is because of the new T.V we got prior to the storm. It's loud, and now we're able to hear voices/noises from it (when it's on, more so when it's quiet outside and inside) then we were able to from our old T.V.

I hate seeing her like this, and I really would like some advice as to help her overcome this fear in anyway possible...

Thanks for your time (and sorry about the length)!!!!

Answer
It's quite possible (and seems closely linked) that your dog's fear is associated with those thunderstorms and she has now begun to generalize the time of day (light level, not by the clock) and other extraneous sounds (such as the neighbor's banging) that didn't formerly worry her.  Trying to "comfort" a dog when it is frightened is a NORMAL response but it makes matters worse because what you are actually doing is REWARDING THE FEAR STATE.  So here's the scenario: lots of thunder (and you're scared too, a tornado is nothing to mess with!), dog perceives your fear to the thunder (not understanding the possible tornado scenario), dog is afraid of the thunder to begin with (as many dogs are) then YOU (her judge of security) are ALSO afraid, then YOU pet, hug, kiss her WHILE you BOTH are afraid...ergo, dog acquires a strong fear response to thunder.  NOW because of those zombie movies (tsk, tsk! lol) YOU are ALSO showing signs of fear for loud noises: dog is WATCHING YOU all the time (they never stop) and she already has a strong acquired fear response to thunder; your fear at LOUD NOISE is instantly associated by her with that conditioned fear response to thunder, so NOW dog has strong fear response to LOUD NOISE (and that would include banging, thundering, etc. on the TV.)

I know very well that it seems almost barbaric to NOT COMFORT a dog when it is frightened.  BUT... touch is a primary reinforcer to a dog and extra attention is also.  The dog is watching YOU for signs of how to react; if she begins to react out of fear to loud noise of any sort, you must make an enormous effort to appear NONCHALANT (even though thunder might scare the heck out of you and the recent zombie movie makes you nervous of your neighbor's thumps) and LEAVE THE ROOM; the dog WILL follow you.  Once she has interrupted her own fear response long enough to follow you, engage her IMMEDIATELY in a behavior you can reward (ask her for a "sit" and give her a nice treat -- for a week or two, carry fat free cheese chunks in small plastic bags in your pocket at times you anticipate her fear reaction.)  If you remove yourself (thereby redirecting her attention) and engage her  (in a trained behavior) and reward THAT behavior (not her fear), you should see (within a couple of weeks) an enormous reduction in her conditioned fear response.  You can't, of course, control the weather!  So you must be vigilant in thunder storms.  Even though you may not have any treats handy, you can STILL show nonchalance, you can STILL leave the room, you can STILL ask for a trained behavior and reward THAT, all the while studiously IGNORING her fear.

At night, when a dog paces and whines, the normal person (like you and I) will want some peace, and so we might get up to get the dog and quiet her down, or even address her (whether to say "it's ok" or "shut up").  These are REWARDS to the dog; again, her anxiety is learned and the more attention you pay to it, the greater it grows.  You may have a few sleepless nights, but you must ignore this pacing and whining.  Also, instead of the floor you might buy her a soft cushy bed to put at the side of your bed.  At times when she is NOT stressed or anxious, sit on her cushy bed, say her name and "Place" until she joins you, then give her a few moments of intense interaction (hugs and kisses, possibly a treat).  If you repeat this several times, you can then begin to say "Place" at random intervals during the day (when she is not fearful) and heavily reward it when she goes toward, or to, her bed.  The dog should build a strong association between the word "place", her bed, and reward over the course of a few weeks of this training.  During the night, if she should demonstrate any anxiety and disturb your sleep (after your initial treatment as discussed earlier), you can interrupt her (clap your hands), then say "Place" and she should go to her bed, whereupon you can praise her and go back to sleep.