The former One Tree Hill star took to Instagram on Monday (17Aug15) to share the sad news of his pet pooch's passing, by posting a collage of photos of Joe throughout the years.

Murray's caption reads: "My best bud & 1st born son Joe, Thank you for everything you've ever done for me. You've been my kindred spirit, my unconditional friend. Thank you for carrying the weight that I could not. You taught me more about selflessness and compassion than I thought a dog could know. Thank you for always keeping the status Quo. Even the dogs at the dog park thank you for keeping the peace.

"Almost 15 years of adventures Joe and I'm so grateful for every minute. Rest easy now bud. Check in on us once and (sic) while would ya... You're missed and always will be. Thx for waiting to meet my son. This family won't be the same without you but so much stronger because of you. Rest in peace Joey. We Love You, Chad, Sarah & Baby Murray."

Murray and his actress wife, Sarah Roemer, welcomed their first child, a baby boy, in May (15).