i think one of the coolest things about a dogs nose is their interaction with humans. when a dog can tell if a diabetic has low blood sugar it just amazes me. their nose is just awesome.
neat story and could just be a coincidence that my pup may have wanted her head scratched but my pup has never been trained to do the exact thing i just mentioned but my GF is a diabetic and one night watching a movie her blood sugar dropped well belle was laying near her all of a sudden got up (like someone was at the door) but turned toward my GF and started whining and poking her (the poking is normal when she was her head scratched but not the whining). and about that time my gf said she needed some juice to get her blood sugar back up. but for about 15-20 mins my pup would not stop looking at my GF (about the time it takes for the body to recover) before she laid back down. again could have been a coincidence but i think it was my pup was concerned about my GF and knew something was wrong.