See more of the story

Warriors and dogs have been partners for more than 2,000 years.

They've gone into battle wearing armor, guarded encampments, tracked enemy combatants, delivered messages, detected mines and other explosives, scouted out snipers, located the wounded, hauled armaments and laid underground telegraph wire.

Loyalty, intelligence, mobility and ingenuity are among the attributes that make dogs valuable to the armed forces. The most common breeds used have been the Belgian malinois, German shepherd and Labrador retriever, but many other breeds have done tours of duty.

An uncharacteristic canine war hero was Sgt. Stubby, a Boston terrier, the most decorated dog during World War I. The official mascot of the U.S. 102nd Infantry Regiment, his exploits included alerting his regiment to mustard gas attacks and incoming shells, locating wounded soldiers and capturing a German soldier by grabbing and holding him by the seat of his pants. In the trenches in France for 18 months, he participated in 17 battles and was a celebrity at home. His story is being made into an animated movie, "Sgt. Stubby: An American Hero," scheduled to be released next April.

Doberman pinschers gained fame during World War II as the "devil dogs" of the Marines. One of the best known was Kurt. After he alerted troops to the presence of Japanese forces on the island of Guam, he was killed by incoming fire. A war dog memorial on the island features a sculpture of Kurt and the words "always faithful." The memorial also includes names of all 25 Marine war dogs that lost their lives there in 1944.

Smoky, a 4-pound Yorkshire terrier, was adopted by Cpl. William A. Wynne after Smoky was found in an abandoned foxhole on New Guinea during World War II. For two years, the little dog nicknamed "Yorkie Doodle Dandy" rode in a backpack, went on combat and reconnaissance flights and ate Spam and C-rations. She proved her valor and value by warning Wynne of incoming shells and, most famously, by pulling a telegraph wire through a 70-foot-long pipe that was only 8 inches in diameter. Her feat saved ground crewmen from a grueling and dangerous dig.

Rigorous training

In contemporary combat, dogs undergo rigorous training. In Afghanistan, military working dogs equipped with cameras scout areas before troops move in. And while they typically don't enjoy the same media exposure as Smoky and Stubby, Cairo, a Belgian malinois and Navy SEAL dog, stepped into the spotlight in 2011 after taking part in Operation Neptune Spear, during which Osama bin Laden was killed.

Last month, five military dogs were honored on Capitol Hill with American Humane's K-9 Medal of Courage, awarded for extraordinary valor and service. The canine honorees were Coffee, a chocolate Lab who sought out IEDs and other security threats in Afghanistan; black Lab Alphie, an explosive-detection dog in Afghanistan who now works for the TSA; Capa, an explosives and patrol dog who also received the Navy and Marine Corps Commendation Medal for meritorious service; black Lab Ranger, who served as an explosives-detection dog in Afghanistan and Iraq; and posthumously, Gabe, who was sprung from a Houston animal shelter and trained as a specialized search dog, a career in which he earned more than 40 awards.

"Soldiers have been relying on four-footed comrades-in-arms since the beginning of organized warfare," said Robin Ganzert, president and CEO of American Humane, "and today military dogs are more important than ever in keeping our servicemen and -women safe."