"Even at the shelter, he had this attitude, like 'I'm going to get out of here,'" she adds. "He saw himself as a survivor. Like he's an old soul. I truly believe he knew he was getting out."
Still, it took two weeks for the shelter to release Mack - thanks to an insistence on only letting a rescue group, rather than an individual, take him out of there.
It was an agonizing wait.
"When you have an injury, two weeks is a long time to sit in a shelter, especially for a little puppy," Fox says.
But last July, Fox, along with fellow rescuer Kickie D'Alfonso, found a small organization willing to sign out the puppy.
From there, it was directly into Fox's arms. And Mack, despite needing urgent medical care, seemed to know all along it would go that way.