The 60-year-old took to her Instagram to share the devastating news with a heartfelt video montage set against the song “You Can Close Your Eyes” by James Taylor. The post features a series of photographs of the family posing with their black and white pup over the years.

In the caption, Ali penned: “I lost my longtime companion. The greatest dog and integral part of our family. He once swam after a giant Elk in a pond. Ate a whole bottle of melatonin and felt nothing. Always devoured all the candy in our Christmas stockings. Slept at the foot of our bed and dreamt running in place. He loved every species. Especially humans. Kissed and cuddled everyone that came through our door. Cooper was unconditionally adored by all. I will miss him with all my heart. See you on the other side, Coop! We still have many squirrels to chase….”

The actress was inundated with support by a slew of star-studded names who flocked to the comments to share their condolences. “A special kind of heartbreak,” wrote Jennifer Garner.