Koontz once told CBS News journalist Anthony Mason about a special moment with Trixie, when they were both on the floor staring into each others' eyes.
"I said, 'I know what you really are.' She raised her head up and gave me this strange expression," Koontz recalled. "And I said, you're not a dog. You're an angel.' And she shot to her feet and ran the length of this hall and stood at the far end."
"I actually had to get down on the floor and coax her to me," Koontz told Mason. "And I brought her to me and it had put the hairs up in the back of my neck. And I said, 'all right. I'll never say that to you again."