"Lost Dog"

Spike's dog went missing for three years. The night after she came home, she helped him with his homework instead of eating it.

There's a story behind that.

Species Change AU: What if the unicorn Twilight Sparkle had been born a dog, in the human world? How would Princess Celestia cope?

_{There's some kind of "Species Change" event or something like that going on right now, idk. They're only allowing one story per author, so whatever.}

_{(Art source: I edited a detail of an official MLP:FiM comic page that 'pencils' originally drew and 'SigmasonicX' uploaded to derpibooru.org.)}