Duane Chapman is best known by millions around the world as “Dog the Bounty Hunter,” a tough as nails fugitive hunter who goes to great lengths to bring bail jumpers to justice.

However, when it comes to the subject of his wife, Beth, Duane’s tough guy exterior melts away instantly, to reveal a loving and vulnerable soul.

Recently, Duane became emotional while discussing his beloved wife’s battle with stage IV lung cancer.

Beth, 51, was recently diagnosed with lung cancer for the second time last November. Although she had beaten cancer once before, this time doctors informed her that the cancer was “incurable.”

Since then Beth has been receiving chemotherapy treatments while she continues to remain active on the road with her husband chasing fugitives and filming their brand new WGN reality show titled “Dog’s Most Wanted.”

“My baby has cancer and she is fighting like hell. I have cried a lot over this because Beth is my everything,” Dog told Daily Mail. “Despite all of the obstacles I have overcome, this is by far the biggest test of my life and mark my words, I will not let her die. She is my rock and my bodyguard. I will do everything I can to keep her here.”

Dog, 66, goes on to say that he’s in awe of his wife’s incredible strength throughout her long bout with cancer.

“If this were me, I would be a big sissy. But not Beth. She is still hitting the ground running with me. Beth is determined cancer won’t slow her down,” he said. “In fact, I am so amazed by Beth’s strength and positive attitude.”

“She has told me repeatedly that if these are her last days on earth she wants to spend every moment with me on the hunt, living life to the fullest and enjoying the time we have left together,” Dog continued. “The best part of my job is having her by my side on every journey. I can’t imagine a day without her and think deep down inside she is always concerned for my safety because she wants the security of knowing I come home to her every night.”