Kim Kardashian is devastated.  Understandably so after her 4-month kitten, Mercy, died last night. The reality star took to Twitter to mourn the loss of the teacup Persian puss gifted to her by boyfriend Kanye West.

“My heart is completely broken” Kim wrote after having to put down Mercy for being diagnosed with a fatal virus often associated with breeding issues.

Kim got Mercy from Kanye in September but because of her allergies, she had to give it away to a friend after deciding not to take doctor-recommended allergy injections.

“I had fallen SO in love with Mercy that I wanted to try everything I could to keep her but I didn’t think it was safe to resort to injections, and it wasn’t fair on Mercy, because I couldn’t play with her or give her as much attention as I wanted to,” Kim wrote, adding: “Mercy deserved a mom who could really give her the time and affection she deserved. I knew that Sydney [Hitchcock], Khloé’s assistant, who had recently lost a cat she had loved and cared for for 17 years, would be the perfect mom for Mercy and Sydney was so excited to have Mercy as her own!”

Sydney is the person who discovered the cancer-like virus in Mercy. “They discovered she had a stomach problem that we weren’t aware of,” Kim explained. “Poor little Mercy died the very next day. It broke not only my heart that little Mercy died at only four months old, but Sydney’s too.

“Mercy was a gentle and loving kitten and we are all going to miss her so much. Thanks to Sydney for making Mercy’s short life one filled with love.”

Kim ended her letter by writing, “RIP Mercy Xo.”