"Eli bit one of them," said Rusk's father, Darrell, recalling the story told to him by other Marines.
After Rusk died Dec. 6, his parents decided they wanted to adopt his dog. They picked Eli up Thursday at Lackland Air Force to take him back to their home in rural South Texas. It was only the second time that a U.S. military dog has been adopted by the family of a handler killed in combat.
Eli wagged his tail furiously when he was brought into a small room inside the 37th Training Wing to meet his new owners. A Marine staff sergeant tried to get the dog to sit obediently while he read a letter of thanks to the family, but he relented after Eli kept lunging forward to sniff Rusk's mother, Kathy.
When the leash was finally handed to Darrell Rusk, his wife and two sons each crouched down to hug and pet Eli, who lifted his front right paw to invite their hands toward his belly. All were crying.
"Every time he called home, it was always about Eli," Kathy Rusk said of her son. "It gave me some comfort knowing that Colton wasn't alone over there."
Military dogs are often adopted after their service is over or if they don't make it through training. But in the case of Eli, who was serving his second stint in Afghanistan when Rusk was shot, it wasn't just a simple matter of Rusk's family asking for him.
Eli wasn't injured in the attack that killed Rusk and was still considered "operational," meaning he could have been transferred to another handler. The Defense Department invests thousands of dollars in training each military dog, all of which come through Lackland. When the Rusks asked about adopting Eli, pulling the dog out of service required permission from the Secretary of the Navy, said Doug Miller, who manages the Defense Department's military working dog program.
Knowing there had only been one other adoption like Eli's, Kathy Rusk said she didn't want to get her hopes up.
"I'm sure it helps the family in the grieving process, because they can touch the last thing that was with him," Miller said.
Eli was assigned to Rusk in May, before Rusk was deployed on his 20th birthday. Kathy Rusk said her son was thrilled by the assignment, especially after growing up surrounded by dogs on the family's 100-acre ranch in Orange Grove, just outside Corpus Christi on the Texas coast.
The two quickly grew inseparable. Military dogs are supposed to sleep in kennels when deployed, but Rusk broke the rules and let Eli curl up with him on his cot. Other times, the dog took up the entire sleeping bag. Rusk ate ready-to-eat meals, so that's what Eli ate instead of dog food, Darrell Rusk said.
"Whatever is mine is his," Colton Rusk wrote on his Facebook page.
Darrell Rusk keeps more than a dozen photos of his son and Eli on his iPhone. One favorite is a photo of Rusk sticking out his tongue to mimic a panting Eli.
Military officials believe Rusk came under fire in Afghanistan after another vehicle in a Marine convoy ran over a hidden explosive. Rusk was shot after the soldiers stopped to secure the area. He might have been trying to tie up Eli.
"The enemy is aware that the dogs are finding their stuff, so it's logical they would pick a dog or handler to take out," Miller said.
Eli will join three German shepherds at the Rusks' ranch. The family put dogs to work hunting hogs when Rusk was growing up - a task that might be easy for Eli, who Darrell Rusk said sniffed out two explosives the day he son was killed.
But Eli's working days are over.
"You're going home and relaxing," said Kathy Rusk, leaning in close to Eli and rubbing his snout. "You're going home."