He's my knight in shining armour with a waggy tail

Coco is a six year old chocolate labrador. He's also a life saver.

His owner Karen has Addison's disease. And when her cortisol levels get too low, she could slip into a coma or die.

Coco can smell when that is about to happen and will "alert" - staring at her or licking her aggresively.

Steve Harris from Breakfast in Dorset 103.8fm went to meet Coco (and Karen!) in Poole.