It's been a bad couple of weeks to be a celebrity's pet.

First Kim Kardashian's four-month-old cat Mercy died from a cancer-like virus, then Miley Cyrus' dog Lila passed away as well. The stars were overcome with grief and took to Twitter to express their sadness.

Like many of us, our pets are considered a part of the family, so it's no surprise that Kim and Miley aren't the only celebrities who publicly mourned the loss of their beloved pets:

Loading Slideshow...
  • Kim Kardashian

    Kim Kardashian's cat Mercy passed away from stomach cancer in December 2012. "It is with deep sadness that I have to tell you all that my kitten, Mercy, has passed away," <a href="http://kimkardashian.celebuzz.com/2012/12/07/rest-in-peace-little-mercy/">Kim wrote on her blog Dec. 7</a>. "My heart is completely broken."

  • Miley Cyrus

    Miiley Cyrus was heartbroken over the death of her dog Lila: "for everyone asking... I have never been so hurt in my life. My heart has never been so broken..... Lila my sweet baby girl has passed away," <a href="https://twitter.com/MileyCyrus/status/278603201698205696">she wrote on Twitter</a>. "Broken. Gonna go MIA for a bit. Need some healing time. Thank you to everyone who has sent love my way. I need it."

  • Jessica Simpson

    In September 2009, Jessica Simpson's dog Daisy was killed by a coyote. The following year the singer remembered the loss of her dog, <a href="https://twitter.com/JessicaSimpson/status/23169729559"> and tweeted: </a> "This day last year my life changed because I lost my baby Daisy Mae - the best pup of all time. Give your dog some extra love today!"

  • George Clooney

    In 2006, George Clooney's 300-lb. potbellied pig, Max, passed away. "He just died, like an hour ago," <a href="http://www.people.com/people/article/0,,1565629,00.html%202006">he told USA Today</a>. "He was as old a pig as the vets had ever seen. I was really surprised, because he's been a big part of my life."

  • Amanda Bynes

    In 2009, Amanda Bynes' teacup Pomeranian, Little Angel, died. <a href="http://www.people.com/people/article/0,,20479654,00.html"> She tweeted: </a> "Little Angel is in heaven now. RIP I love you."

  • Kelly Osbourne

    In 2010, Kelly Osbourne's Pomeranian puppy, Woody, died. "My life just could not get any worst (sic) right now," <a href="https://twitter.com/MissKellyO/status/18872464439">she wrote on Twitter.</a> "I come home to find my dog woody is dead."

  • Oprah Winfrey

    In 2007, Oprah's 2-year-old Golden Retriever Gracie died after she choked on a plastic ball. In O magazine, <a href="http://www.people.com/people/article/0,,20046895,00.html">Winfrey wrote of her dogs death</a>, noting that Gracie "did more living in two years than most dogs do in 12" – and that is the lesson to be gained from her beloved young golden. "This dog lived every moment as though it were her last."

  • Miranda Lambert

    One of Miranda Lambert's dogs passed away in March 2012, and the singer <a href="https://twitter.com/Miranda_Lambert/status/165491231105884161">turned to Twitter to express her grief: </a> "My best friend, father-in-law, and now my dog Dixie. My dog died thursday. My parents just told me. Headed now to bury my friend of 20 years."

  • Gisele Bundchen

    In October, Gisele's Yorkie pup, Vida, passed away. The supermodel mourned her death, and<a href="http://www.facebook.com/photo.php?fbid=10152174248905083&set=pb.148286545082.-2207520000.1355434446&type=3&theater"> wrote on Facebook</a>: "My best friend, she will always live on in my heart. Let’s never take for granted the unconditional love that our animals show us every single day."