The Internet Is In Mourning After Boo, 'The World's Cutest Dog,' Dies At Age 12 😢

On the night of Friday, January 18th, a dog named Boo, who has amassed an insane amount of popularity over the past decade for being the "world's cutest dog," passed away peacefully in his sleep.

The announcement was shared with the world via Boo's Facebook fan page an Instagram.

An announcement was made on Facebook as well:

Boo and his friend, the late Buddy, had over 600,000 Instagram followers and over 16 million Facebook fans.

"I brought Boo home in the spring of 2006 and so started the greatest, most heartwarming friendship of all time," wrote the pup's owners. They said Boo's health issues began when his pal, Buddy, passed away.

"Shortly after Buddy died, Boo showed signs of heart issues. We think his heart literally broke when Buddy left us."

Boo's humans say they could never have fully anticipated the impact Boo has had on the world outside their little dog family.

"Since starting Boo's FB page, I've received so many notes over the years from people sharing stories of how Boo brightened their days and helped bring a little light to their lives during difficult times. And that was really the purpose of all this...Boo brought joy to people all over the world."

"Boo is the happiest dog I've ever met. He was so easy going that we never had to bother with training. He made the manliest of men squeal with delight over his cuteness and made everyone laugh with his quirky, tail wagging personality."

Boo's Instagram page stands as a monument to all things Boo (and Buddy, who was just as adorable) and can hopefully provide some comfort for our hearts.

Here are some of Boo's cutest moments:

Good night, sweet Boo, and flights of angels sing thee to thy rest.