My theory is that dogs' may have a greater sensitivity (hearing wise) then cats. La Neige
, my former husky was deeply affected by thunder. Even before we humans knew a thunderstorm was coming, she would become anxious and start walking pacing around.
During the worst storms, she would try to find the farthest place to lie down, away from the windows and since it was a New York apartment, there really wasn't any place for her to go to hide. So she usually hide under a table or a desk especially if someone was sitting there.
Not all dogs are affected by thunderstorm. One time I was walking 3 dogs for work when a sudden summer thunderstorm hit 2 of the dogs were a-okay but the black lab in the bunch refused to walk at all (despite the intense rain pouring on top of us). Thankfully we ducked under an store eave and like many summer squalls, the rain only lasted 3 minutes. But even though the rain stopped, the thunder continued in the distance and the black lab still was uberhesitant to walk back to the dog kennel where I worked.