Meanwhile, it isn't the first time the famous pooch's social media accounts have written touching messages since the star's passing.
Gary's Twitter account - which, like his Instagram, is run by a handler and isn't affiliated with Carrie - posted a sweet tribute to the icon when she passed away last year.
They wrote at the time: "Saddest tweets to tweet. Mommy is gone. I love you @carrieffisher ... I'll still be waiting for you....... I was always by your side but best of all you were always by mine. #RIPCarrie
"Love knows no season, It haunts the soul eternally. Coolest dog ever posing with the coolest human ever #RIPCarrie #CarrieFisher (sic)."
Carrie has always been close to her pet dog and she previously claimed he was like Elvis because he attracts so much attention.
She said: "I want to get his tongue pierced. It's like wandering around with Elvis. I've gotten so much attention with it that it seemed like the most natural, ridiculous move - if there could be a combination like that - to put him on the Internet."