The 21-year-old posted a moving memorial to the canine, her pet of three years on Twitter Tuesday, saying "Today is the 2nd worst day of my life.
"I don't wanna say it because I don't want it to be real... But my precious baby Floyd has passed away. I am broken," the "We Can't Stop" singer tweeted, before sending a sad, disturbing message about her state of mind in the wake of the dog's death.
"I am miserable."