The end of the story is tragic; some readers find it heartbreaking. Few readers can forget the final image of Doodle, a little boy lying in the rain, covered in his own blood, with his brother holding his lifeless body.
Although the end of the story is incredibly sad and disturbing, from a literary perspective, it completes the thematic development of the story. The big brother's selfish pride destroys Doodle, a truth the brother (who is the narrator of the story) does not recognize until it is too late.
Since readers become so emotionally attached to Doodle, it would be nice to imagine a different ending. Perhaps at the end of the story, the narrator runs away from Doodle, but he turns around and goes to find Doodle in the storm before it is too late.
In another ending, perhaps the narrator "comes to his senses." He realizes how exhausted Doodle has become, takes his little brother home, and vows to love and accept Doodle for the wonderful little boy he is. This conclusion to the story would require that the narrator grows up before, rather than after, a tragedy occurs.
leave it as it is
i would not change it