Lewis Hamilton is mourning the loss of his beloved dog.

The British racing driver has announced that his 12-year-old bulldog, Roscoe, died on Sunday evening after being admitted to an animal hospital with pneumonia the week before and placed in a coma.

Lewis, who missed a Formula 1 tyre test in order to be by Roscoe's side, told his followers on Monday that he had made the "hardest decision of (his) life" to have his dog put down.

"After four days on life support, fighting with every bit of strength he had, I had to make the hardest decision of my life and say goodbye to Roscoe," Lewis wrote in the post. "He never stopped fighting, right until the very end."

"I feel so grateful and honoured to have shared my life with such a beautiful soul, an angel and true friend," he continued. "Bringing Roscoe into my life was the best decision I ever made, and I will forever cherish the memories we created together."

The sports star adopted Roscoe in 2013, along with another dog named Coco. Coco died from a suspected heart attack in 2020, having suffered from health issues since birth.

Elsewhere in his post, the Ferrari driver noted that he had never had to have an animal put down before.

"It is one of the most painful experiences and I feel a deep connection to everyone who has gone through the loss of a beloved pet," the 40-year-old added, before expressing his gratitude for Roscoe.

"Although it was so hard, having him was one of the most beautiful parts of life, to love so deeply and to be loved in return," he wrote. "Thank you all for the love and support you've shown Roscoe over the years. It has been so special to witness and feel."

As part of the post, Lewis shared a series of photos of himself with the bulldog, including one of him as a puppy.