It's quite common for dogs (and other animals too for that matter) to be fearful or even phobic about certain noises; with fireworks and thunder being two particularly notorious culprits. There's no consensus about why some dogs are affected more than others; reactions vary from mild to moderate to extreme, but there is a risk of the emotional response worsening over time if your dog is left to cope with it on her own.

Are there ways you can help your dog? You bet there are, and here are some 'best practices' on how to help your dog manage:

Before getting started, please note:

~ All dogs are different. Each dog is a unique combination of its genetics, upbringing and experiences, so there is no convenient 'one size fits all' solution that applies equally for all dogs.

~ These 'best practices' are not a 'cure' for your dog's fear/phobia (behaviour modification is an entirely different conversation). Instead, these are coping strategies to help you lessen your dog's emotional distress as much as possible.

~ Additionally, If your dog has a noise phobia that is significant enough that you're worried about her psychological and/or physical well-being, please contact your veterinarian for assistance

1. Don't leave your dog unsupervised outdoors. A panic-stricken dog may try to escape its environment in its attempt to escape from the noise it is fearful of. Dogs may dig under, jump over or chew through whatever prevents them from fleeing and, because of their panic state, they are not conscious of where they are running or how to get home again.
    

2. If at all possible, don't leave your dog unsupervised indoors either. Even when indoors, if the dog is fearful enough it may attempt to dig, jump or chew in order to escape from the noise. Be very cautious about attempting to crate your dog or otherwise confine your dog as it's possible for her to damage herself (cracked teeth, lacerations, injured paws) trying to escape from a confined space such as a crate or room when in a panic state.
    

3. There are some aids which may help your dog cope with the fireworks activities. The swaddling effect of a wrap or 'Thundershirt' is known to help some dogs, and there are some nutraceuticals (ie: non-prescription) that people report having varying degrees of success with. Two things though:
   
   (a) If you are going to experiment with these types of aids, make sure you follow the supplied instructions and introduce or apply them in advance of the fireworks getting underway.
   
   (b) It's best not to think of these as 'magic pill' solutions. Instead, think of them as 'pieces of the puzzle' which, when used in combination with other best practices, can possibly provide an accumulative benefit for your dog.
    

4. Some dogs may want to hide under blankets, under a bed, in a closet, etc., so (within reason) let your dog choose the place where she can hide from the noise and feel safest, and then do your best to make that spot as comfortable as possible for her. In additional, close the window and draw the drapes/blinds to prevent as much of the noise and 'flash' as possible.
   
   It has to be remembered that the fear your dog experiences is not a voluntary emotion... there's no logic or 'thinking' involved... so, as previously mentioned, you want to make sure the fear doesn't escalate into full blown panic due to feeling confined or trapped. Accordingly, allow your dog to have free and easy access to her safe haven area(s). 
    

5. Here's a personal recommendation that has significantly helped my dog Nova: When your dog has chosen her 'safe haven' spot, create a wall of noise that will help smother the sound of the fireworks. 

    

   Nova always chooses to run downstairs to hide in the family room, so I have our portable dehumidifier ready (and running) and the television turned on and at a volume that can be clearly heard above the noise of the dehumidifier. The dehumidifier creates a steady wall of 'white noise' and then the television program creates an unpredictable distracting noise. In combination, these two noises are sufficient in muffling all but the closest and loudest fireworks, and Nova can even sleep in peace while fireworks are snap, crackle and popping outside.
   
   If you don't have a dehumidifier, the noise of an air conditioner unit is similar, but you can also use a portable fan if it's loud enough (try the highest setting). If you don't have a television in your dog's 'safe haven' area, then use a radio or stereo/music and turn up the volume so it can be heard above the 'white noise' of the other device. 
    

6. During the fireworks episodes, there is absolutely nothing wrong with giving your dog attention and reassurance.
   
   MYTH BUSTING TIME:  There's a persistent myth that suggests coddling or otherwise reassuring your dog makes their fear-based behaviour worse in a "Yes, you're right to be afraid!" type of way. How wide-spread is this belief? I think a significant number of people learned this myth from a particular (male) celebrity dog trainer, but you can even find it in blogs written by veterinarians, in 'Pet Health' websites, etc.
   
   The belief is that coddling your dog positively reinforces your dog's fear. On the surface this might sound logical, except for the fact that the four quadrants of Operant Conditioning (with positive reinforcement being one of those quadrants) relate to voluntary behaviour... like when you're training your dog to sit. The fear/phobia your dog experiences with fireworks is an involuntary emotional response, so it can not be operantly reinforced or punished. And yes, there's plenty of research that supports the busting of this myth. 
    

7. Never admonish or punish your dog for her fear-based behaviour because it is not voluntary... it's beyond her control. Instead, do your best to improve her physical environment and emotional state using the best practices listed here (and other appropriate best practices you may be aware of), and then encourage and positively reinforce any desirable behaviours she is able to provide. 
   
   With Nova, I practice items 1, 2, 4, 5, 6 and 7 noted herein, and I stay with her in her 'safe haven' area for periods of time and also encourage our other dog (who doesn't happen to be afraid of fireworks noise) to join us if he is willing. With all of these best practices in place (including the background noise) it's usually pretty easy to get Nova to settle down next to me, to play some simple games of 'find it' and for her to get comfortable enough where she can drift off to sleep at times. All in all, a vast improvement compared to when I first adopted her. 

Again, all dogs are different, but I'm hoping some of these tips may be of help to you and your dog!  :)