The Big Bang Theory star announced the death of her family dog Petey with a touching Instagram post Thursday night.
"Anyone who knows me, knows Petey. He was basically the first dog I ever had," she captioned a photo collage of her and the chihuahua-dachshund mix. "I was gifted him on my sweet 16, by my bf at the time.. I was afraid I would get in trouble so I hid him in my bedroom for 3 days until my parents found out- they said I had to take care of him if I was to keep him, that he would be mine!"
The 30-year-old continued: "Here we are 15 years later. My folks gave him the greatest life and he taught us what it meant to love an adoption pup. I have since named my corporation after him (peteypie inc) and he has brought a lifetime of joy and laughs to our entire family. I know he will now enjoy doggie heaven where there will be an abundance of greenies just for him. This little guy, I will never ever forget…"
The dog's passing arrives on what would've Cuoco and her ex Ryan Sweeting's two-year wedding anniversary.
The couple married on New Year's Eve in 2013, and 21 months later, announced their decision to separate exclusively to PEOPLE. Cuoco filed for divorce from the tennis star shortly after, citing irreconcilable differences.
On Thursday, she attended a small New Year's Eve party in Los Angeles.