LONDON - British soldiers and military dogs gathered at a London army barracks Thursday to honor a fallen hero with selfless courage, nerves of steel - and four legs.

Theo, a bomb-sniffing springer spaniel who died in Afghanistan on the day his soldier partner was killed, was posthumously honored with the Dickin Medal, Britain's highest award for bravery by animals.

Theo worked alongside Lance Cpl. Liam Tasker, searching for roadside bombs in Helmand province, a Taliban stronghold.

Tasker, 26, died in a firefight with insurgents in March 2011, and Theo suffered a fatal seizure hours later. Tasker's mother, Jane Duffy, says the pair were inseparable. She's convinced Theo died of a broken heart.

"They'll be watching us, and they'll be so proud," she said. "I just wish they were here to get it themselves."

Since 1943, the Dickin Medal has recognized gallantry by animals serving with the military, police or rescue services.

Theo is the 28th dog to receive the medal, awarded by animal charity PDSA and named for its founder, Maria Dickin.

One of the earliest winners was Rip, a mongrel found abandoned in a bomb shelter and adopted by a London air raid warden. He was credited with finding more than 100 people trapped in rubble by German bombs during the 1940 Blitz.

Another World War II hero was Rob, a collie who joined British commandos in more than 20 parachute operations behind enemy lines in North Africa and Italy. His medal citation said that "his presence with these parties saved many of them from discovery and subsequent capture or destruction."

Dogs have also been honored for service in Bosnia, Iraq, Afghanistan and during terrorist attacks.

Pigeons' homing instinct makes them excellent messengers, and more than 200,000 served with British forces during World War II. Some 32 were awarded the Dickin Medal for carrying back vital information from the frontline.

Feathered medal-winners include Gustav, a pigeon serving with the Royal Air Force, "for delivering the first message from the Normandy Beaches from a ship off the beach-head" on June 6, 1944, the day of the D-Day landings.