Retired Marine Cpl. Megan Leavey and Sergeant Rex were both injured by an explosive device while on patrol together in Iraq in 2006.
Leavey's injuries ended her career, and she tried to adopt Rex. But the military turned her down because Rex recovered and returned to active duty.
When she learned Rex was about to be retired, she tried to adopt him again, and was finally successful.
"We got through it together and recovered together after. I'm just glad that we're both together now and this is able to happen," Leavey said.
Leavey had to cut through a lot of red tape to adopt Sergeant Rex. She got help from veterans groups and New York Sen. Chuck Schumer.