Kim Kardashian is deeply saddened, and we don't blame her.
Mercy was put down after being diagnosed with a fatal, cancer-like virus often associated with breeding.
West gave Kim the kitten in September, but after a few weeks she developed allergies and one doctor recommended injections if she wanted to be able to keep living with her pet.
"I had fallen SO in love with Mercy that I wanted to try everything I could to keep her," Kim wrote, "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. Mercy deserved a mom who could really give her the time and affection she deserved. I knew that Sydney, 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 Hitchcock and her boyfriend were the ones who were caring for Mercy when she suddenly got sick after several routine trips to the vet resulted in clean bills of health.
"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," she concluded. "RIP Mercy Xo."