Kim Kardashian's Heart 'Completely Broken' After Kitten 'Mercy' Dies

Brett Kaffee/Thibault Monnier/

Kim Kardashian's beloved white kitten that has been featured in many of the reality star's Instagram pictures has died.

"It is with deep sadness that I have to tell you all that my kitten, Mercy, has passed away. My heart is completely broken," Kardashian wrote on her blog Friday.

According to her blog, Kardashian didn't realize she was allergic to cats when she first got Mercy.

PHOTOS: Keeping Up With the Kardashians

"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," Kardashian wrote. "Mercy deserved a mom who could really give her the time and affection she deserved."

PHOTOS: Celebrity Animal Lovers

She gave the kitten to her sister Khloe's assistant, Sydney, who just lost a cat.

However, Mercy got sick with a "stomach problem that they were not aware of" and the feline died.

"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," Kardashian wrote.

PHOTOS: Crazy Cats