Thousands of dog lovers are mourning the passing of a 12-year-old Pomeranian dubbed the “World’s Cutest Dog.” Boo had over 560,000 fans on Instagram, and 16 million on Facebook. The beloved pooch’s passing was announced on Friday:

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 have been in a long time.

Boo’s best pal, Buddy, died in the fall of 2017 – there is speculation that Boo could no longer continue with his broken heart. His people explained:

I brought Boo home in the spring of 2006 and so started the greatest, most heartwarming friendship of all time. Shortly after Buddy died, Boo showed signs of heart issues. We think his heart literally broke when Buddy left us. He hung on and gave us over a year. But it looks like it was his time, and I’m sure it was a most joyous moment for them when they saw each other in heaven.

And a few final words on Boo’s behalf:

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.
Thank you to all of you for following along on their silly adventures over the past 10 years. They sure had a LOT of fun.

With love and our deepest gratitude,
Boo’s humans

Boo not only had an impressive social media presence – he also made multiple television appearances, was featured in a comic book series and also a book, Boo – The Life Of The World’s Cutest Dog.

(Screenshot of Boo via Instagram)