Rob Lowe Mourns the Death of His 14-Year-Old Family Dog: 'A Curious, Adventurous Boy'

Rob Lowe/Instagram

Rob Lowe's family dog Wayne has passed away.

On Tuesday, the 57-year-old actor paid tribute to the late pet with an emotional "In Memoriam" on his Instagram page, featuring a sweet shot of Wayne standing chest-deep in a pool.

"We are heartbroken that our beloved Wayne passed away today. He was 14 years old," Lowe captioned the post. "He was a curious, adventurous boy who loved playing chase, stealing snacks, and swimming."

RELATED: Sam Asghari Says He and Britney Spears Will Not Crop New Puppy's Ears, Calls the Practice 'Selfish'

The star added, "He was also a wonderful actor who did all his own stunts on our backyard Instagram show 'Abandon Crab.' We love you, Wayne! RIP 🐾🙏🏽🕊"

Lowe received an outpouring of support in the comments section from friends and family, including his brother Chad Lowe.

"Godspeed Wayne 💔," wrote the actor, 53.

RELATED: What Causes the Zoomies? Vet Weighs in on What Makes Your Pet Race Around the House

Rob's youngest son Edward Matthew said Wayne "is in heaven swimming and stealing bread" now. "Abandon crab forever," he added.

The 9-1-1: Lone Star actor's eldest son John Owen predicted the pup went "Straight to Heaven ❤️."

Stephane Cardinale - Corbis/Corbis via Getty Images Rob Lowe

Both Katherine Schwarzenegger and Patrick Schwarzenegger chimed in as well.

Katherine, 31, wrote, "Poor Wayne!!! We love you Wayne!" while Patrick, 28, added, "Don't forget drinking jacuzzi water! ❤️❤️."

Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories.

Three weeks ago, Lowe and his family welcomed a female Jack Russell terrier puppy.

"Say hello to the newest member of the family, Daisy," Lowe shared on Instagram on Sept. 23 alongside an image of the wide-eyed pup.

"I'm a goner for her," he added.