PHOTOS: Sully Bush a constant at his master's side

Sully H.W. Bush brought countless hours of happiness to George H.W. Bush after the death of his beloved wife Barbara. (Sully H.W. Bush Instagram)

Bush family

President George H.W. Bush with his service dog Sully in 2018

Sully H.W. Bush brought countless hours of happiness to George H.W. Bush after the death of his beloved wife Barbara. (Sully H.W. Bush Instagram)

Sully H.W. Bush brought countless hours of happiness to George H.W. Bush after the death of his beloved wife Barbara. (Sully H.W. Bush Instagram)

Sully H.W. Bush brought countless hours of happiness to George H.W. Bush after the death of his beloved wife Barbara. (Sully H.W. Bush Instagram)