Transcript for The Special Bond Between a Young Girl With Rare Genetic Disorder and Her Service Dog

Finally, the little girl and her really great Dane. Meet Bella and George. Bella is 11, in the fifth grade, 43 pounds. George, a great Dane, 131 pounds. He acts smaller than he actually. Reporter: Bella was diagnosed with a syndrome when she was just 2 1/2. That rare genetic disease that attacks the bones. There is no cure. Before George, Bella couldn't walk on her own. Chef re she relied on crutches or a wheelchair. But this year, that all changed. Because Bella met George. The connection, immediate. Since getting George, Bella has put away her crutches. He helps her get from class to class on her own. How you doing, bell? Good! Reporter: She gets to her desk and he gets some sleep. When I had crutches, I couldn't walk at all. But now I can. Reporter: Then it's off to gym. As he guides her through those gym doors. Oh, he helps me walk. I lean on him like a crutch. Reporter: Sledding last winter. And every night, it's bedtime together before they do it all again. Death of the cop known as

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