How did john take care of Buck to make him strong and healthy again?

John took care of Buck by providing him with proper nutrition, regular exercise, and a safe environment to recover. He ensured that Buck received enough food to regain his strength and took him on long, invigorating walks to build his stamina. Additionally, John offered affection and companionship, which helped Buck regain his confidence and trust. This holistic approach contributed to Buck's overall health and well-being.