Sofia found Oscar when she was eight years old but was initially forbidden from keeping him by her distant and controlling father Alan Rikkin. However, she managed to change his mind by promising she would diligently train Oscar and keep her grades from slipping.
One day, while being walked by Sofia, Oscar slipped his leash to go after a squirrel and, overexcited and frightened, bit Sofia as she reached for his collar. Alan was outraged when the pair returned home. He sent Sofia away to his doctor to get stitches and then had Oscar shot. Alan later justified his actions by telling his daughter that he did not like seeing her get hurt.