What exactly did this woman want?  She stated she was severely allergic to animals.  The crew asked her to leave the plane but she refused.  Why would she want to remain in the plane if she was allergic to animals?  Maybe she wanted the animals and owners removed instead.  Aside from this.  Only call police officers to remove someone from an aircraft as a last resort.  They have no nice way of removing people.  It usually ends up people getting dragged creating a scene ending up on social media.