KINGSPORT, Tenn. -

It’s the first day of high school for Jack, a 13-month-old black Labrador Retriever, but he's not your average dog -- Jack is a certified Diabetes Alert Dog.

He's walking the halls with his handler, high school junior Kersey Reynolds.

Reynolds has type one diabetes and Jack is trained to signal a warning if her blood sugar gets too low. "He just catches wind of it because there's a diabetic scent that's given off. When he smells it, he just puts a paw on me, and if I don't stop he just keeps at me until I do," explains Reynolds.

Jack has been training with the Reynolds family for months, but this is the first time he's attended the high school. He seems to be taking it easy, but even when he's resting, Jack is still working.

Jack's trainer, Bill Creasy, also has diabetes and is a part of the Diabetes Alert Dog Alliance, a national group which recently set new certification standards for these service dogs.

Creasy stopped by school to observe the first day and says it was a good start for the duo. "He was laying there with his head on her backpack, sound asleep. The only time I saw him raise his head was when the teacher went out and shut the door. He raised up and then just plopped right back down," he said.

Jack will be by Reynold's side 24 hours a day, seven days a week, even when she heads to college, which provides some peace-of mind for her mom. "It's nice to know that Jack will be in the car with her, to know that Jack is in the room with her at college while she's away, especially at night," says Kelly Reynolds, Kersey’s mom.

This first day at school is just the beginning of what we’re told will be a life-long bond between a service dog and his handler.

The Reynolds family and Creasy say this day would not be possible without the great support of the Kingsport City School System.

Kelly Reynolds encourages people to do plenty of research before buying a service dog. For more information visit www.diabetesalertdogalliance.org and www.69hdflh.com.