Hello @Nina. Welcome to the community forum. Good for you for trying different approaches until you found what worked best for the Jack Russell. It sounds as if there were quite a few storms while you were there 
Thanks @anon49809275 for raising this question, and thanks to everyone who posted a response. There’s a doggo and his pet parent who are much happier because of your help.
The backstory: Recently I took care of an older dog who was new to an area prone to thunderstorms. When the dog’s owner told me how frightened the thunder made him, I suggested a Thundershirt. I had never heard of them prior to reading this thread, but the owner agreed it was worth trying to keep her pup calm and happy. She ordered the shirt just before leaving, and I worked with the dog during the sit to get him comfortable with it.
I just received word that now, when he senses a storm is coming, the pup goes to his owner and asks for his Thundershirt. Once he has it on, he calmly goes about his business. No more shaking or cowering in the corner for him.
Thanks for all of your insights on this! 
3 Likes
We tried a Thundershirt on our noise-reactive Golden. It had zero effect, probably because she was already so anxious by the time we got it on her, that it was too late. She sensed barometric pressure changes, so she would be nervous 4 hours before an actual storm hit. We also tried CBD oil, prescription meds and the like. The only thing that helped her somewhat was to be in a more confined space (our kitchen) and with her sister, who had no reactions at all. We also played animal shows on tv, to distract her a bit. In the end, we just decided it was easier to come home if the weather report showed something coming up, and we made sure to be home during fireworks seasons. I am curious if anyone was able to desensitize their dogs in other ways?