Dogs are indeed man's best friend. Sully, the late ex-President George H.W. Bush's service dog, has proved it by showing his unconditional love to his owner up to the very end of his line.

During the funeral services held at the U.S. Capitol Rotunda, the Labrador retriever stood by the former president's casket for the last time offering his last service to a friend on Tuesday afternoon.

The former President's furry friend was seen wearing his special vest embellished with an American flag and the seal of the President of the United States on it. His partner for the event was Tom Ridge, who was the former Secretary of Homeland Security under Bush's leadership.

To attend this heartbreaking moment, Sully traveled for more than 1.5 thousand miles from Texas to Washington D.C. According to E! News, the pup was accompanied by the Bush family throughout the trip.

Though Sully has just been able to be with the late ex-President for only six months, the friendly canine became very close to him. The spark between them happened instantly right after the fur baby arrived in their residence in June before the First Lady Barbara Bush's death. Bush's wife died the first quarter of this year.

Through the short time they were together, the two shared a very special friendship that everyone admired. He didn't just make life easier for the late President during his last days, but he also became a great part of his family.

As Bush's service dog, Sully lived up to his name and helped Bush in every way he could, as posted by Today. Olivia Poff, America's Vetdogs & Guide Dog Foundation, said, "Sully was trained specifically to help Bush opened doors. He was trained to summon in an emergency type of situation. And he was trained to retrieve dropped items, which is very helpful especially if you are wheel chair user."

The photo of the adorable pup lying quietly beside the casket of his friend attracted the attention of the media and the internet. This made people ask what will happen to Sully after Bush's death.

America's Vetdogs & Guide Dog Foundation declared that Sully, after the event, will eventually return to the center and stay there for a while. After that, he will then be going back to work in Walter Reed and help other veterans and active duty personnel who are suffering from physical problems.

Bush's family said, "As much as our family is going to miss this dog, we're comforted to know he'll bring the same joy to his new home, Walter Reed, that he brought to 41.