When a massive, scarred rescue dog wandered toward the pediatric cancer ward window, hospital security reacted with immediate concern. But what the frightened animal did next left nurses, parents, and doctors quietly wiping tears from their eyes.

Now the hospital bed was the center of his universe.

Aggressive leukemia treatments had destroyed most of his immune system. Doctors had no choice but to place him inside a sterile isolation room where even visitors had to wear protective gear.

No grass.

No dirt.

No animals.