By Rebecca Frankel
Best Defense chief canine correspondent

Plastered across the top of Pfc. Colton Rusk's Facebook page are photographs of a black Labrador Retriever, named Eli, who always looks like he's smiling. Rusk was a dog handler who had enlisted in the Marines right out of high school and Eli, the four-year-old bomb-sniffing dog, was his partner.

The pair was serving in Afghanistan when Rusk was hit by Taliban sniper fire on Dec. 6, 2010. Eli was the first to reach him where Rusk fell. The dog crawled on top of Rusk's body,  ferociously protecting his handler "[snapping at the] other Marines who rushed to [Rusk's aide]. 'Eli bit one of them,' said Rusk's father Darrell, recalling the story told to him by other Marines."

Colton Rusk did not survive the attack. He was 20 years old when he died. 

In all of the articles that have been published since Rusk's death -- and there are many -- this fallen handler and his war dog are always described the same way: They were best friends. Family members recount how Rusk broke protocol so that Eli could be by his side all the time, sharing his cot instead of sleeping in the kennel. Rusk's mother, Kathy, told AP that ""Every time he called home, it was always about Eli. She said it gave her comfort to know her son "wasn't alone over there."

It was this bond that prompted the Rusk family to petition the military to let them adopt Eli after their son's death. And while Eli is a young canine, still at the beginning of what might have been a long career as an IED detection dog, the military saw fit to make an exception, and granted Eli special permission to retire from service.

The Rusk family traveled to Lackland Air Force base on Feb. 3 to pick Eli up and bring him back to their Texas ranch where he will begin his retirement, joining the family's three other dogs in the home where Colton was once a boy. (You can watch a video of the Rusk family -- Colton's parents and his two young brothers -- reunite with Eli here.)

I found Colton Rusk's obituary; it says that he was a star athlete in high school -- a two-year letter man in football, and a three-year letter man baseball -- and that he was known especially for his "beautiful smile." Eli's name is listed first among the family members who survive him.

As a side note, our war-dog feature turned one year old last week. Thanks to all who have shared your comments and your stories -- keep them coming. We wouldn't be doing this without you.

(Hat tip: Andrew Swift)

Update: The DoD just put up a slide show of Eli along with an excellent article with some touching quotes about Colton and Eli from the Rusk family.