She first sent them a tweet asking them to follow her "or I'll break my dog's neck." Then, when they inevitably ignored her, she followed this up with a tweet showing herself cradling her dead dog. [nydailynews.com]
But as David Emery points out, the picture of her and her dog dates back a couple of months. Plus, she's been making similar threats via tweet for quite a while.
In other words, we can safely dismiss her as just another disturbed, attention-seeking individual online. And she got the attention she wanted. She also admitted via tweet a few days ago, "Are people still going on about this f*cking dog thing, I was trolling!!!! STOP." And then twitter suspended her account.