WWE Superstar Sheamus just shared some heartbreaking news ... announcing the death of his dog, Betty -- just days after she completed her last round of chemo.
The Grand Slam Champion mourned the devastating loss in a lengthy Instagram post on Wednesday ... saying the past few years were incredibly special with her in his life.
"Even though our time together was cut far too short, I'll never regret the decision to make her part of our family. She brought so much joy and happiness into our home and into the lives of everyone who met her," Sheamus said.