When Kaelyn, who is known as K.K., was 2 months old, she was diagnosed with mastocytosis, a rare condition in which someone has too many mast cells, which release histamine as part of the body’s immune response. When there are too many mast cells, even the smallest triggers, such as stress and temperature change, can cause a massive release of histamine, which can cause the blood pressure to drop and the body to go into shock. A service dog named J.J. helps Kaelyn and her family live a more normal life.