In 2003, Steven Bochco, the writer/producer of "Blind Justice," wrote a mystery novel called "Death by Hollywood". In it, the main character shows a friend of his a short story that he wrote about a guy who gets telepathic messages from his dog for movie and TV show ideas, and one of them was about a detective who gets blinded in the line of duty and goes back to the force with a guide dog. Steven Bochco decided to use that idea for this TV series.
Detective Jim Dunbar:
I need you - seriously, y'know - like the flower needs the rain.