Kristi Noem defends controversial decision to shoot her dog: 'I can understand why some people are upset'

South Dakota Gov. Kristi Noem is defending a controversial account she shares in a new book about killing her 14-month-old dog, Cricket, in an incident she said was decades ago.

"I can understand why some people are upset about a 20 year old story of Cricket, one of the working dogs at our ranch, in my upcoming book -- No Going Back," Noem, who is speculated to be among the leading contenders to be Donald Trump's choice of a running mate, wrote on X on Sunday.

"The book is filled with many honest stories of my life, good and bad days, challenges, painful decisions, and lessons learned," Noem wrote.

Touting her "years of public service," including leading her state during the onset of the COVID-19 pandemic, Noem went on to write, "My hope is anyone reading this book will have an understanding that I always work to make the best decisions I can for the people in my life."

In her new book, "No Going Back: The Truth on What's Wrong with Politics and How We Move America Forward," set to be released next week and obtained by ABC News, Noem writes about what led up to her decision to personally kill Cricket, a wirehair pointer -- a choice that has been widely criticized by animal advocates and others as inhumane and excessive. Democrats have also joined the outcry.

In the book, Noem describes the dog as having an "aggressive personality" and being "out of her mind with excitement."

According to the book, as first reported in The Guardian, things apparently came to a head for Noem, when, on the way home from a pheasant hunt one day, Cricket attacked a family's group of chickens, acting, she says, like a "trained assassin."

When Noem eventually got control of the dog, by grabbing her collar, she writes, "She whipped around to bite me."

"I hated that dog," Noem writes, claiming Cricket was "untrainable."

"This was my dog and my responsibility, and I would not ask someone else to clean up my mess," Noem writes. "I stopped the truck in the middle of the yard, got my gun, grabbed Cricket's leash and led her out into the pasture and down into the gravel pit."

"It was not a pleasant job," she writes, "but it had to be done."

Noem's stories of putting animals down don't end there.

After shooting her dog, Noem writes that she also killed a goat her family owned that she calls "nasty and mean." She describes the goat as being a "problem for years," writing that male goats "urinate on their own heads and beards while in rut" and that the specific goat loved to chase her kids, scaring them.

In her book, Noem compares both decisions to put down the animals to a leader needing to make difficult decisions.

"It's often messy, ugly, and matter-of-fact, dealing with a problem that no one wants to deal with," she writes, adding, "I guess if I were a better politician I wouldn't tell the story here."

On Friday, Noem doubled down on X amid backlash over killing her dog.

"We love animals, but tough decisions like this happen all the time on a farm," Noem wrote. "Sadly, we just had to put down 3 horses a few weeks ago that had been in our family for 25 years."

She expanded on her experiences in her statement on Sunday.

"The fact is, South Dakota law states that dogs who attack and kill livestock can be put down. Given that Cricket had shown aggressive behavior toward people by biting them, I decided what I did," she wrote.

"Whether running the ranch or in politics, I have never passed on my responsibilities to anyone else to handle. Even if it's hard and painful," Noem wrote. "I followed the law and was being a responsible parent, dog owner, and neighbor."