Liam and Theo were a team, fast friends doing a dangerous job -- searching out roadside bombs laid by insurgents in Afghanistan.

The jovial British soldier and his irrepressible dog worked and played together for months, and died on the same day. On Thursday they came home, flown back to Britain in a somber repatriation ceremony for the soldier remembered for his empathy with animals and the companion he loved.

Lance Cpl. Liam Tasker, a dog handler with the Royal Army Veterinary Corps, was killed in a firefight with insurgents in Helmand Province on March 1 as he searched for explosives with Theo, a bomb-sniffing springer spaniel mix. The dog suffered a fatal seizure hours later at a British army base, likely brought about by stress.

Military officials won't go so far as to say Theo died of a broken heart -- but that may not be far from the truth.

"I think we often underestimate the grieving process in dogs," said Elaine Pendlebury, a senior veterinarian with animal charity PDSA. "Some dogs react very severely to their partner's loss."

She said it was not uncommon for pets to respond to an owner's death by refusing food and becoming sick -- and the bond between working dogs and their handlers is especially close.

"The bonding that I have seen between soldiers or police and their dogs is fantastic. When you see them working together, it's really one unit."

A military Hercules plane carrying Tasker's body and Theo's ashes touched down Thursday at a Royal Air Force base in southwest England. As the funeral cortege of black vehicles drove slowly away, it was saluted by a long line of military dog handlers, their dogs at their sides. A black Labrador retriever sat quietly beside its handler as the hearse carrying the flag-draped coffin disappeared from view.

At the nearby town of Wootton Bassett, where people line the streets in a mark of respect each time a dead solder is repatriated, dozens stood silently -- some with dogs at their feet -- as Tasker's friends and family laid roses atop the hearse.

The Ministry of Defense said Theo's ashes would be presented to Tasker's family later at a private ceremony.

Tasker, 26, from Kirkcaldy in Scotland, spent six years as an army mechanic before joining the military working dog unit in 2007. He felt he had found his calling.

"I love my job and working together with Theo," Tasker said in a profile of the pair released by the Ministry of Defense before his death. "He has a great character and never tires. He can't wait to get out and do his job and will stop at nothing."

The soldier and the 22-month-old dog had been in Afghanistan for almost six months, uncovering roadside bombs and weapons in a dangerous daily routine.

Theo became a bit of a military celebrity last month after the defense ministry released photos and video of him and Tasker to highlight the lifesaving work of military dogs. The footage, now deeply poignant, shows Theo -- energetic, ears cocked, tail wagging -- alongside Tasker searching a compound for explosives.

The ministry said then that Theo had been so successful -- finding 14 hidden bombs and weapons caches, a record for a team in Afghanistan -- that the dog's tour of duty had been extended by a month.

Tasker was the 358th British soldier to die in Afghanistan since the 2001 U.S.-led invasion. Theo was the sixth British military dog killed in Iraq or Afghanistan since 2001.

There are calls for Theo to receive the Dickin medal, which since 1943 has recognized wartime bravery by animals, from carrier pigeons to a World War II commando collie.

The loyalty of some dogs is legendary, from Greyfriars Bobby, a 19th-century Skye terrier who guarded his master's Edinburgh grave for 14 years, to Hachiko, a Japanese dog who awaited his owner's return at a train station every day for years after the man's death. Both are commemorated with statues.

Tasker's father, Ian, said Theo would have been devastated by Liam's death.

"I truly believe when Theo went back to the kennel, that that would have a big, big impact because Liam wasn't there to comfort him," he told ITV news.

Tasker's mother, Jane Duffy agreed. "I'm not nurse or a vet (but) I would like to believe (Theo) died of a broken heart to be with Liam," she told the broadcaster.

Tasker's colleague's recalled the soldier's bond with his dog and zealous attention to duty in tributes released by the defense ministry.

"A natural with animals, he had an affection for his dog that truly was a window to his soul," said Maj. Alexander Turner, a commander of Tasker's unit.

He "was here to save life, finding explosive devices that kill more farmers than combatants in our area," Turner said. "His fortitude and zeal for that perilous task was humbling; it imbued us all with confidence. He used to joke that Theo was impossible to restrain but I would say the same about Lance Corporal Tasker."

Tasker's uncle, Billy McCord, said the soldier had been due to leave Afghanistan soon and worried about being separated from Theo.

"He actually said at one point that when he finished his tour he was not sure what would happen to his dog and that he could be separated from his dog," McCord told the local Courier newspaper in Scotland. "That was preying on his mind, but they are not separated now."