The Hollywood star, who shares 19-month-old daughter Matilda with her fiancé, also mentioned that the pitbull mix would fight, not only with Blue, but with other dogs as well.

“Long story short, she’s a very special dog to me, as you all know,” she shared.

“And when the love of my life came into my life, Tom, who is also a mega dog lover,” she continued, “and he moved across the country with his beautiful German Shepherd, Blue, a couple years ago, unfortunately, Blue and Shirley started getting into some mega fights.”

Shirley was “determined to kill” Blue, she added.

As she feared for the safety of both dogs and others, the actress said she made the excruciating decision to re-home Shirley with her pet handler, Tony, and his wife, Angie, who had been taking care of the dog for years before her recent death.

“She got a very aggressive bone cancer that came on very quickly,” she said.

Kaley tearfully reflected on Shirley’s long life, saying, “She was almost 14 years old, which is an unbelievable life for a dog. And I just wanted to share her story and what we had to do.”

Although the Flight Attendant actress said the decision to re-home Shirley was best for everyone, including the pet, her confession sparked outrage among some social media users.