I believe that deep down in her heart she truly feels that our rake in an evil being bent on destroying her little dog life, therefore it must be destroyed.
She may look sweet and innocent, but don't let her fool you. As soon as Mr. Rake enters the scene she quickly morphs into Olive the wonder dog with one thing on her mind: the rakes total and complete annihilation. That's right. Total and complete.
Note to rakes everywhere:
if you have fulfilled your yearly duties, please stay safely locked in the garage. There's just no telling when Olive may feel the need to rid the entire world of you evil monsters.