Not sure what you're asking.
Some soldier (army or marine I'm not sure) was posting photos or a blog a while back, showed photos of a stray dog they adopted, but eventually had to let go.
Not the same dog, I'm sure, but I don't doubt other dogs have been adopted and then ran away or were set loose.
Just did a quick google search - here's another, please read the story.
http://www.washingtonpost.com/wp-dyn/content/article/2005/10/19/AR2005101902344.htmlA War Dog's Faithful Friend
Back From Iraq, Md. Reserve Officer Launched A Mission to Rescue the Buddy He Left Behind
By Ruben Castaneda
Washington Post Staff Writer
Thursday, October 20, 2005; Page B01
Laurel lawyer John E. Smathers, a captain in the Army Reserve, returned from a year in Iraq with a broken arm, a wrecked knee and a chest full of medals.
During his tour, Smathers helped thwart a bank robbery and assisted in recovering stolen Iraqi artwork. He survived an ambush and a high-speed auto crash.
But when he got back in March 2004, he was determined to complete a final mission: to rescue Scout, a dog he and other soldiers had adopted, from the increasingly bloody streets of Baghdad and bring him to his Howard County home. Scout was resolute, loyal. So was Smathers.
<snip>
photo caption:
After a 17-month quest to bring his adopted dog from Iraq to Maryland, Capt. John E. Smathers was reunited with Scout in late August at Dulles International Airport. Scout had acted as a watchdog for Smathers's Army Reserve unit, above, in Iraq. (By Michael Robinson-chavez -- The Washington Post)