JOINT BASE LEWIS-McCHORD, Wash. — Meet Tracker, a five-year-old, sixty-pound Belgian Malinois and a graduate of the Military Working Dog School at Lackland Air Force Base, Texas. He's also one of the Army's first five openly transgender military police dogs, assigned to the 42nd Military Police Brigade at Joint Base Lewis-McChord.

"We took to each other pretty quickly," said Spc. Jeffrey Grassley, a military policeman and dog handler partnered with Tracker. "I mean, it's a little weird that they tell me to call him a 'him,' since he's obviously a female dog, and there was that time last month when he was laid up for a few days after he gave birth to a litter of puppies, but we've really forged a close working friendship."

Tracker, who was raised as a female dog under the name Regina, first identified as a male during the initial breeding and selection process the military uses to screen potential military working dogs.

"Looking back now, it was pretty obvious that she was — sorry, He — was a little different," said Tech Sgt. Walter Flaherty, one of Tracker's trainers. "He didn't really say much, obviously, but you could just sort of tell."

During play time, Flaherty said, Tracker would consistently engage in behavior normally associated with male dogs, and whenever he would go into heat, would go after the females pretty aggressively, almost totally ignoring the male dogs.

"He would only play with blue chew toys, and for some reason, he really liked watching reruns of 'Xena: Warrior Princess,'" Flaherty added.

Paws Across The Rainbow, the nation's leading advocacy group for LGBT animals, hailed the move, calling it a "landmark achievement for all military working animals, no matter what their sexuality."

"We hope that this will serve as an example throughout the military that being transgendered is simply not a reason to discriminate against competent and talented military working animals of all species, said spokesman Pat Riley, while also calling on the Army to provide no-cost gender-reassignment surgery for the dogs "as a gesture of tolerance and recognition of the diverse nature of today's military working animals."

Some of the more traditional, conservative elements within the Army might not be so ready to embrace such a radical change, however.

The all-male caisson horses of the 3rd Infantry Regiment, or "The Old Guard," long entrusted with the solemn honor of bearing the caskets of fallen warriors and deceased U.S. presidents, have drawn fire for refusing to allow female or openly LGBT horses within its ranks, and the regiment's command team is unapologetic about that fact.

"As long as I'm here, that's the way it's going to stay," said Command Sgt. Maj. Samuel J. Stoker, The Old Guard's senior noncommissioned officer. "I'll resign before I'll see some fancy-prancing fairy-horsey bear my president down the National Mall."

Stoker may be the last of a dying breed, however. Polling data suggests that most service members are indifferent to the idea, with 15 percent of those polled say they would "definitely" or "very likely" be willing to work with an openly LGBT military working animal. In that regard, Tracker and his four compatriots are pioneers in more than one way: If all goes well, according to sources within Defense Secretary Chuck Hagel's office, their service may open the door to full integration for all LGBT military working animals.

As for Spc. Grassley, Tracker's handler, he says he doesn't concern himself with the larger political implications of Tracker's assignment to the unit, and just treats him as his K-9 partner, nothing more.

"Every once in a while he tries to hump my leg, which is kind of pointless since he doesn't have a penis, but it's just a male-dominance thing, and besides, it's pretty funny."