The question's use of the word "pathetic" deems a subjective answer. What this means is that the question will be answered one way by one reader and another way by another. The answer to the question differs based upon a reader's personal thoughts only.
Therefore, one could justify that the story "The Black Cat" proves to be more "pathetic." Justification for this answer comes from the fact that the elephant in Orwell's story is "ravaging the bazaar." The cat, from Poe's story, is not doing anything when the narrator inflicts harm upon the creature.
The speaker in "The Black Cat" is simply led about by his own feelings and warped mental capacities. This is very unlike the speaker in "To Shoot an Elephant" where the choice to kill the elephant comes from the narrator's assumed views regarding the crowd's expectations regarding the elephant's death. Also, the narrator is legally given the right to kill the elephant based upon law. The speaker in "The Black Cat" has no legal right to cause the cat harm--instead, the action can be justifiably considered animal cruelty.