Military practice forbade Dana from adopting his canine comrade, as the dog was still considered a highly trained military asset.
But after their plight hit the headlines, Congress passed, and Bush signed, a new law lifting the prohibition on adopting dogs before their working lives were over.
The Air Force then let the adoption go ahead.
Rex's work in Iraq included searching vehicles at checkpoints and scouring buildings for booby traps and explosives.
The pair was riding in a Humvee vehicle together last June when the bomb went off.
Both Dana and Rex were listed as guests in First Lady Laura Bush's box by an official White House press release.
It was believed to be the first time an animal had been allowed into the hallowed halls of the House of Representatives to hear a president in action.
Senator Edward Kennedy's dog has however been known to patrol congressional hearing rooms when his master is at work.
