Schumer held a celebration Sunday in his Manhattan office for "Sergeant Rex" and former Cpl. Megan Leavey, who spent years fighting for permission to take the aging dog home.
"They performed the most dangerous job in the military," the New York Democrat said of Leavey's mission in Iraq, which entailed using the highly-trained dog to identify roadside explosives.
The pair saved "countless" lives, Schumer said.
Both were badly injured on a patrol in 2006. With 11-year-old Rex in declining health, the senator said time was crucial.
On Sunday, while Rex barked happily at news cameras, Schumer presented the 28-year-old ex-Marine with more than 21,000 signatures from people who had urged military officials to release the dog to Leavey.
After she retired in 2007 with a Purple Heart, Rex kept working.
She'd been trying to adopt the dog but was stymied by bureaucracy until she asked Schumer to intervene.
The senator supports a bill that would speed up retired military dog adoptions, introduced by Sen. Richard Blumenthal, D-Conn.
The legislation would reclassify dogs from "equipment" to "canine members of the armed forces," while allowing the military to accept travel benefits and coordinate veterinary care with an outside not-for-profit agency. The bill would also ensure that "excessed" dogs cannot be abandoned in a war zone as equipment, with no way home, Schumer said.
Since 2000, it has been illegal for the military to euthanize any working dog that is considered adoptable.
There are currently 2,700 dogs on active duty in the U.S. military.
Of the 444 that left in 2011, 52 were transferred to other government or law enforcement agencies and 276 were privately adopted, according to an Air Force report. The other 116 died while on active duty, some of natural causes and others euthanized for debilitating illness or because they were too dangerous for adoption.
Rex was retired when he turned 10 and was deemed unable to work.
He arrived Tuesday from Camp Pendleton, the Marine base in California, and now romps through Leavey's backyard in Rockland County, north of New York City.
After not seeing Rex for four years, Leavey was afraid he wouldn't remember her. "But it was like I'd seen him yesterday," she said. "The bond that we have is incredible."
In the senator's office, Rex rolled onto his back, paws in the air, chomping on a stuffed toy.
Schumer gave him some bipartisan dog biscuits - one bag with elephants, the other donkeys, because the Marine pair "saved us all, Republicans and Democrats, and we thought Rex would be happy munching on both," the senator joked.
The combat dog also got a rubber yellow cab, "so he won't have to chase New York taxis!"
Handler and dog have both healed and Leavey now works for a New York private security firm, handling dogs.
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