Kim Kardashian has been left heartbroken after a kitten given to her by boyfriend Kanye West was put down due to ill health.

Mercy was a gentle and loving kitten and we are all going to miss her so much

The Stronger hitmaker surprised the reality TV star with a fluffy white cat called Mercy in September (12), and Kardashian showed off the cute pet to fans by posting pictures on Twitter.com.

However, she suffered a severe allergic reaction to the cat and was forced to give Mercy away to her sister Khloe's assistant, Sydney, who rushed the pet to the vet last month (Nov12) after it fell ill.

The vet diagnosed the kitten with an untreatable virus, and the Kardashian clan decided to have the animal put down.

In a statement, Kardashian says, "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".