A shelter puppy who suffered the heartbreak of seeing each of his siblings ... the shelter posted a video to its TikTok page highlighting how Sawyer was "sad" and "alone" since seeing his family head ...

A shelter puppy named Sawyer has been left to watch as each of his siblings get adopted while he's left behind, hoping and waiting to get a forever home of his own.

There have been a few times he just plops his butt on the ground and gives me those sad “puppy dog eyes” and then we are off for another 10 or so minutes… hoping to run into somebody for him to greet.

Sawyer the puppy was having a hard time getting adopted ... the shelter posted a video to its TikTok page highlighting how Sawyer was "sad" and "alone" since seeing his family head off to forever ...