Halsey Mourns the Sudden Death of Their Dog Jagger: 'The Worst Week of My Life'
Axelle/Bauer-Griffin/FilmMagic Halsey
Halsey is grieving the loss of their dog, Jagger.
The "Without Me" singer revealed on Instagram that their dog died after suffering from a "progressive condition" called Myelomalacia on Friday.
As they reflected on Jagger's death, Halsey, 27, confessed in Saturday's heartbreaking message that "this has been the worst week of my life."
The singer said they had expected for Jagger to be "old and rickety and grumpy" upon his deathbed — "Unfortunately that is not how it happened for us."
RELATED: Halsey Celebrates Son Ender Turning 6 Months Old with Finger-Painting and Banana Oatmeal Cake
"Jagger was 5 years old and yesterday we lost him to a progressive condition called Myelomalacia. It is sudden and uncommon and unfair with a catastrophic prognosis," they noted.
Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories.
"Within three days, my beautiful baby boy went from chasing imaginary birds around the yard and laying in my lap turning his ears up at the sounds of Sesame Street, to having paralysis spread through his body by the hour. It was sudden and shocking and I still haven't even really processed it," Halsey continued.
Halsey adopted Jagger in early 2017 when he was only "a few weeks old." They named the pet after Mick Jagger and he was frequently featured on live streams as well as some interviews. The "Bad at Love" singer also runs an Instagram account for their canine companion that boasts over 10 thousand followers under the username @champagne_puppiii.
The If I Can't Have Love, I Want Power musician also explained that Jagger was their "very first love, who taught me how to be a mommy." "My sweet, sarcastic, so very human boy ... Every single person who had the privilege of meeting jagger will never forget him. He was that special," they wrote.
RELATED: Halsey Shares Adorable Video Compilation of Son Ender: 'Can't Wait for a Year Full of You'
Halsey concluded the message by describing Jagger's death as "the most visceral loss" they've ever felt.
"Like the absence of a vital appendage. Every single second of my day that once revolved around his little habits and routines is now full of just emptiness and silence," they shared. "If you loved Jagger along with me, thank you for giving him the best life the bestest boy could have ever had. ??????."