It was a week of highs and heartbreaking lows for George Stephanopoulos and wife Ali Wentworth.

Just days after the proud parents celebrated their eldest daughter Elliott’s graduation from Brown University, the family was struck by a devastating loss back home — their beloved dog, Cooper.

“He Was More Than a Pet — He Was Family”

Ali, 59, took to Instagram with a moving tribute that had fans and celebrities alike tearing up. “I lost my longtime companion. The greatest dog and integral part of our family,” she wrote alongside a touching video montage of Cooper through the years.

From chasing elk in a pond to stealing Christmas candy, Cooper was more than a pet. He was family. “He once swam after a giant elk… ate a whole bottle of melatonin and felt nothing… kissed and cuddled everyone that came through our door,” she wrote. “He loved every species. Especially humans.”

The slideshow showed sweet moments between Cooper and the entire Stephanopoulos-Wentworth clan, reminding followers just how deeply the pup was woven into their lives.

“I will miss him with all my heart,” Ali wrote. “See you on the other side, Coop! We still have many squirrels to chase…”

Celebrity Friends Send Love

She later posted a second video with “more of sweet Cooper,” prompting a flood of love in the comments. Friends and fans rallied to support her, including A-listers who had also met the four-legged family member.

“A special kind of heartbreak,” wrote Jennifer Garner. Sean Hayes added, “Aww. I loved him. So sorry honey!” And Bravo’s Andy Cohen shared, “Ali! I’m so sorry!!! I feel a connection to Cooper through Wacha. I am so sad about this.”

From Graduation Cheers to Goodbye Tears

The loss came on the heels of a major family milestone: Elliott’s graduation from Brown University. Ali celebrated with humor and heart, writing, “She did it! Happy graduation to an incredible human being who has her father’s brain and my legs… and if it was the other way around, she’d be screwed.”

Ali and George, who also share 19-year-old daughter Harper, continue to lean on each other during what’s become an emotional week.

Cooper may be gone, but he’s clearly left paw prints on the hearts of everyone who knew him.