She very well may have had an altercation with a rat. Bubbles used to take on rats nearly as large as she was. She was lucky never to be injured by one. And Coon once brought home a rabbit! She had babies to feed (she was a foundling...pregnant.), and she had to lift her head all the way up to bring it home. So, some cats don't seem to notice the size of their potential prey!
Love All Life, Thank You For Posting! :)