Boo the Pomeranian, who was branded the world's cutest dog, has died from a 'broken heart' aged 12.
The news was announced on Boo's Facebook page, which has more than 16 million likes.
Joining his best friend Buddy
The Facebook post said: "With deepest sadness, I wanted to share that Boo passed away in his sleep early this morning and has left us to join his best friend, Buddy.
"Our family is heartbroken, but we find comfort knowing that he is no longer in any pain or discomfort. We know that Buddy was the first to greet him on the other side of that rainbow bridge, and this is likely the most excited either of them has been in a long time."
His human companions believe Boo's heart 'literally broke' after the passing of Buddy, who died in September 2017, as he had been showing signs of a heart problem ever since.
They also thanked the staff at Adobe Animal Hospital and Sage Veterinary Centers for caring for both of their dogs.
'We love you with all our hearts'
Boo made many TV appearances and released a book: Boo - the life of the world's cutest dog.
His human companions added: "Boo, we love you with all our hearts and will miss you until the day we meet again. Have fun running around with Buddy and creating adorable mischief wherever you guys go."