To transform the sentence into a personification, you can give the dog human-like qualities or emotions. Here’s a revised version:
"The little dog, startled by the brilliant fireworks, leaped over the fence as if it were trying to escape a thunderous roar, and in a burst of excitement, raced down the street like a joyful child chasing after a parade."
This version imbues the dog with emotions and actions typically associated with humans, enhancing the expression of personification.