The 'Believe' hitmaker is mourning the death of his beloved pooch, who lived with his grandparents in Ontario, Canada, because of his busy schedule, reported In Touch Weekly.
Posting an old photograph of himself and his pet, Bieber wrote on Instagram: "RIP Sammy you were the best puppy ever (sic)."
The 20-year-old star revealed in 2009 that the rescue dog became his 'friend' when he moved to a new city and didn't know anyone.
While Bieber was devoted to Sammy, his treatment of some of his family's other animals has sparked controversy.
However, it emerged last month that Jeremy had left the dog with trainer Trevor Dvernichuk in February and never returned to pick it up.
