The White House announced Saturday that the Bidens' 13-year-old German Shepherd Champ passed away peacefully at home.
"We love our sweet, good boy and will miss him always," a statement released on Twitter said.
Champ was a beloved long-time companion for the first family who was with President Biden and the family during his time as Vice President in the Obama administration as well.
The Bidens adopted their other dog Major in 2018 from the Delaware Humane Association. Champ joined the family after the 2008 presidential election that made Joe Biden vice president.
In January Champ joined the rest of the family as he and Major became the first pets to live at the White House since the Obama administration.
President Biden's statement Saturday said of Champ's final days, "Even as Champ's strength waned in his last months, when we came into a room, he would immediately pull himself up, his tail always wagging, and nuzzle us for an ear scratch or a belly rub. Wherever we were, he wanted to be, and everything was instantly better when he was next to us,"
"We love our sweet, good boy and will miss him always," the president's statement said.
The Bidens could occasionally be seen walking their two dogs on the White House South Lawn, and the dogs sometimes would join the president on trips to Camp David or visits home in Delaware.
Major has drawn headlines for his bad behavior in the past. Major caused Biden to suffer a foot injury in November, after the then-president-elect tripped over the younger dog while they were playing. Major and Champ were brought home to Delaware at one point, and Major went through training after the younger dog had two separate biting incidents at the White House and an unknown dog appeared to have pooped in a White House hallway.
Champ, who showed his age in recent months in his graying fur and slower gait, was often a more tranquil presence.
The Bidens are expected to bring a cat to the White House to join the family sometime soon.
The Associated Press contributed to this report.