"I never cried in Iraq. I never cried when I left for Iraq. I never cried when I saw my family for the first time or my friends when I came back from Iraq," Holt told "Fox News @ Night" anchor Shannon Bream in the new series, "Hero Dogs."
"But when I closed the gate, me and [military working dog] Jackson sat in the kennel and we cried for a good hour, hour and a half," Holt continued, "I knew that was the last time I could possibly ever hold this leash because he had to start building a bond with this new handler."
The new series "Hero Dogs", now available on Fox Nation for "Grateful Nation" month, details the stories of military working dogs and their handlers. The first episode featured Holt and his Belgian Malinois.
The pair deployed to Iraq in 2006. On just their second day in the warzone, Jackson was tested and quickly proved that he was going to be an asset to Holt and his fellow troops.
"My very first mission with Jackson... was supposed to be a simple sweep of a school just outside of Baqubah, Iraq," remembered Holt.
"We went in and we started searching for weapons caches, explosives, anything that military working dog Jackson would find or any insurgents it might be hiding in the building."
The mission turned out to be anything but simple. Within five minutes, Jackson alerted Holt to a cache of machine guns, ammunition and bomb-making material.
Next, Holt was ordered to do a sweep of the exterior of an 8-foot-tall mud-brick wall surrounding the compound and several farm trailers parked along the perimeter.
"Jackson came up to a trailer and then stopped. I almost tripped over him for a second, but he stopped me from going forward. When I looked down to see what was wrong with him -- within a foot of where we were actually stepping was a tripwire," Holt remembered.
"At the end of that tripwire were three mortar rounds," he said, "The IED would have went off and probably killed me and the three other members of the Army that was with me that day."
Jackson would prove himself time and time again -- keeping calm under fire and even enduring a 16-hour wait in a ditch, while he and Holt awaited rescue on one ill-fated mission detailed in the show.
Holt and Jackson would form an incredible bond of partnership and friendship, which made their separation all the more difficult.
When Holt retired from the U.S. Air Force he had to leave Jackson behind.
"When he left, he was only allowed to take Jackson's collar and leash," narrated Bream, "And as Jackson continued his military career, Holt struggled to adjust to life as a civilian."
"I had nightmares from the day that I got back and gave Jackson up. I would wake up in panic attacks," Holt told Fox Nation.
Then finally, after seven years of struggle, Holt received the phone call that he had been hoping for -- Jackson was available for adoption.
"I thought it was a joke at first because everybody here knew how much I wanted Jackson and that I talked about him," he remembered.
Holt didn't hesitate and his Indiana neighbors, who had heard all of Harvey's stories about his friend and partner over the years, donated enough money for a plane ticket so that Jackson could be picked up in Washington D.C. and finally brought home.
"The bond between the military working dog and his handler is eternal. You'll never forget that dog. You have a once in a lifetime dog. And Jackson was my once in a lifetime dog," said Holt.