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Monday, March 13, marks National K9 Veterans Day, a day to honor and commemorate the service and sacrifices of American military and working dogs throughout history. According to American Humane, it was 75 years ago today that the U.S. Army first established the War Dog Program, or “K9 Corps,” to train man’s best friend to become the military’s best canine asset. The dogs of war who have served alongside soldiers throughout history aren’t just good dogs — they’re great dogs.

The most well-known working dogs include Smoky, the female Yorkshire Terrier rescued from a foxhole by Cpl. Bill Wynne during World War II who visited injured soldiers and helped string communication lines between military outposts in the Pacific Theater; Gander, the enormous Newfoundland “promoted” to sergeant of an Royal Canadian rifle team who terrified the bejesus out of unsuspecting Japanese soldiers and saved his unit by literally playing fetch with a Japanese hand grenade; and Lex, the German Shepherd, who faithfully served alongside owner Cpl. Dustin Lee until the corporal’s death in Iraq in 2007. And who can forget Sgt. Stubby, the original war dog:

The four-legged trailblazer earned fame for his battlefield heroism while attached to the Army’s 102nd Infantry Regiment, 26th (Yankee) Division, during World War I. A stray at the time, Stubby met his best friend and handler, Cpl. Robert Conroy, during training in Virginia. Smuggling Stubby aboard the SS Minnesota in October 1917, the two set sail for France.

On the battlefield, Stubby distinguished himself with the uncanny ability to detect incoming artillery, mustard gas, and even enemy soldiers. The war dog once latched onto a German infiltrator that was dressed as an American soldier. He was battle tested, even sustaining injuries in combat, but it was Stubby’s friendly demeanor among his fellow soldiers that endeared him to his unit.

Sgt. Stubby visits the White House to call on President Calvin Coolidge in November 1924.Photo via Wikimedia Commons
Sgt. Stubby visits the White House to call on President Calvin Coolidge in November 1924.

As of 2015, there were about 2,500 war dogs operating in service of the U.S. military, with around deployed 700 overseas with U.S. troops at any given time. Below, we pay tribute to some of America’s finest canine warriors. And remember: When things get tough, cry havoc and let slip the dogs of war:

1. Tarzan

Tarzan, a German Shepard Military Working Dog assigned to the 100th Military Working Dog Detachment practices controlled aggression with his handler, SGT Jessey E. Csech at the Panzer Kaserne military working dog compound near Boeblingen, Germany, Feb. 23, 2017. Photo via DoD
Tarzan, a German Shepard military working dog assigned to the 100th Military Working Dog Detachment practices controlled aggression with his handler, Sgt. Jessey E. Csech at the Panzer Kaserne military working dog compound near Boeblingen, Germany, Feb. 23, 2017.

2. Ali

U.S. Air Force Staff Sgt. David Macdonald, dog handler, poses for a photo with military working dog Ali at Bagram Air Base, Afghanistan, in 2013. DoD photo
U.S. Air Force Staff Sgt. David Macdonald, dog handler, poses for a photo with military working dog Ali at Bagram Air Base, Afghanistan, in 2013.

3. Jerry

Pfc. Heaven Southard, an Army military working dog handler with the Directorate of Emergency Services, Area Support Group - Kuwait, releases her military working dog (MWD) “Jerry” during a demonstration of MWD capabilities at Camp Arifjan, Kuwait, on Mar. 7, 2017.DoD photo
Pfc. Heaven Southard, an Army military working dog handler with the Directorate of Emergency Services, Area Support Group – Kuwait, releases her military working dog “Jerry” during a demonstration of MWD capabilities at Camp Arifjan, Kuwait, on March 7, 2017.

4. Elmo

Elmo, 628th Security Forces military working dog, sits beside his handler Senior Airman Trey Weston, 628th Security Forces military working dog handler, before starting his workday, Joint Base Charleston, S.C., August, 17, 2016. DoD photo
Elmo, 628th Security Forces military working dog, sits beside his handler Senior Airman Trey Weston, 628th Security Forces military working dog handler, before starting his workday, Joint Base Charleston, South Carolina, Aug. 17, 2016.

5. Lara

Army Spc. Ian Long, a military working dog handler from Fort Campbell, Kentucky, reassures Lara, his military working dog, while she is being examined by U.S. Army Central medical personnel Dec. 19, 2016 at Camp Arifjan, Kuwait.DoD photo
Army Spc. Ian Long, a military working dog handler from Fort Campbell, Kentucky, reassures Lara, his military working dog, while she is being examined by U.S. Army Central medical personnel Dec. 19, 2016 at Camp Arifjan, Kuwait.

6. Bak

U.S. Air Force Staff Sgt. Jessica Woodall, 820th Base Defense Squadron military working dog handler, poses with her dog, MWD Bak, Feb. 19, 2016, at Moody Air Force Base, Ga. Bak works as an explosive detector dog with Woodall during deployments and secret service missions.DoD photo
U.S. Air Force Staff Sgt. Jessica Woodall, 820th Base Defense Squadron military working dog handler, poses with her dog, Bak, Feb. 19, 2016, at Moody Air Force Base, Georgia.

7. Joker

Joker, a 4-year-old military working dog assigned to Fort Rucker, Ala., grabs hold of Sgt. Oscar Rodriguez, military working dog handler, 483rd Working Dog Detachment, Fort Huachuca, Ariz., during a demonstration for students at Paradise Valley High School, Phoenix, Feb. 8. Photo via DoD
Joker, a 4-year-old military working dog assigned to Fort Rucker, Alabama, grabs hold of Sgt. Oscar Rodriguez, military working dog handler, 483rd Working Dog Detachment, Fort Huachuca, Arizona, during a demonstration for students at Paradise Valley High School, Phoenix, Feb. 8.

8. Raider

Lance Cpl. Joel A. Garcia runs a box search with his military working dog Raider at Combat Town, Okinawa, Japan, Jan. 24, 2017. DoD photo
Lance Cpl. Joel A. Garcia runs a box search with his military working dog Raider at Combat Town, Okinawa, Japan, Jan. 24, 2017.

9. Prada

U.S. Air Force Staff Sgt. Timothy Glover, 99th Security Forces Squadron, Nellis Air Force Base, Nevada, rewards his military working dog Prada for discovering hidden explosives by giving her a toy, Nov. 10, 2016. DoD photo
U.S. Air Force Staff Sgt. Timothy Glover, 99th Security Forces Squadron, Nellis Air Force Base, Nevada, rewards his military working dog Prada for discovering hidden explosives by giving her a toy, Nov. 10, 2016.

10. Jop

Jop, a military working dog with the 49th Security Forces Squadron, poses for the camera during a “play time” session at Holloman Air Force Base, N.M., on Dec. 7, 2016.DoD photo
Jop, a military working dog with the 49th Security Forces Squadron, poses for the camera during a “play time” session at Holloman Air Force Base, New Mexico, on Dec. 7, 2016.

Who’s a good boy? You’re all very good boys.