LONDON - A U.S. military service dog that saved the lives of thousands of troops by sniffing out explosives has been awarded the highest honor of bravery by a British animal charity.

Lucca the German shepherd completed six years of active service with more than 400 patrols in Iraq and Afghanistan.

U.S. Marines say she protected the lives of thousands of American and allied troops.

"She's incredibly smart and loyal,” said her handler, U.S. Marine Gunnery Sgt. Christopher Willingham. “I thought I knew a lot about her, but when you deploy with a dog in a combat environment and you spend seven days a week with them for seven months, you truly find what the depth of a bond is between a dog and a handler."

Both Lucca and Willingham traveled to London on Tuesday, where the 12-year-old German shepherd received the British People's Dispensary for Sick Animals' (PDSA) Dickin Medal for bravery in battle — the 67th recipient of the honor, which stretches back to World War II.

U.S. Gunnery Sergeant Christopher Willingham stand
U.S. Gunnery Sergeant Christopher Willingham stands with Lucca, after the German shepherd received the PDSA Dickin Medal, awarded for animal bravery, in London, April 5, 2016.

"Her uncanny bravery in the face of adversity, both on and off the battlefield, proved to be an invaluable asset and served to make her the most deserving of being awarded the Dickin Medal," said PDSA Director General Jan McLoughlin.

Lucca was so good at her job that not one human was killed or injured during any of her patrols.

Bomb detonates

On her final mission in March 2012 in Afghanistan, Lucca discovered a 14-kilogram roadside bomb. As she searched for additional devices, a second bomb detonated. She instantly lost her front left paw and suffered severe burns to her chest.

Within 10 minutes, a medical evacuation helicopter was taking Lucca for emergency surgery. Her leg had to be amputated, but otherwise she made a full recovery.

Retired from her role, Lucca now lives in California with Willingham — who says she's adjusted well to life outside the military.

"Most importantly, she enjoys just being a dog,” he said. “Just relaxing, laying on the couch, going for family walks instead of combat patrols — and we spoil her in her well-deserved retirement."