Kim updated her blog tonight with the sad news — and an admission that she had actually given the cat away weeks ago after she found out she was allergic to it:

It is with deep sadness that I have to tell you all that my kitten, Mercy, has passed away. My heart is completely broken.

When I first got Mercy, I had never lived with a cat before and so I had no idea that I was allergic. I thought that it might pass, but after a few weeks I decided to go visit two separate allergists, one of whom said my allergies wouldn’t get any better unless I started taking 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. Mercy deserved a mom who could really give her the time and affection she deserved. I knew that Sydney, Khloe’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 gave Mercy a loving home, but after a couple of weeks Mercy got really sick and Sydney had to rush her to the vet. They discovered she had a stomach problem that we weren’t aware of. 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. RIP Mercy Xo

And now a few photos of the adorable little kitten: