(CNN) — Sully H.W. Bush, a yellow Labrador service dog who worked with the late former President George H.W. Bush, will be traveling with Bush’s casket on his flight to Washington, DC, according to a source familiar with the plans.

Jim McGrath, Bush’s spokesman, posted an image of Sully next to Bush’s casket on Sunday along with the caption, “Mission complete.”

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A highly trained service dog, Sully will now go back into service to help other veterans and is likely to be going to Walter Reed National Military Medical Center.

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He was trained by America’s VetDogs and developed his own huge following on Instagram. America’s VetDogs is a charity that provides service dogs to veterans, active-duty service members and first responders with disabilities.

Sully went to work with Bush this summer after former first lady Barbara Bush passed away earlier this year.

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