Florida - When sisters Sydney and Montanna noticed that their dad Craig was becoming increasingly withdrawn and lonely, they reached into their bag of tricks and gave him Dozer, a cute puppy dog.

Daughter Montanna recently posted the best moments of the past three years in a TikTok video, which has been rewarded with viral status.

But the dog's "Gotcha Day" celebration was bittersweet, since there had been much sadness before his adoption.

Craig had been through a lot, losing his wife early on and raising his daughters alone with no desire to marry again. After Sydney and Montanna moved out and the family dog died, Craig lost more and more energy.

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He used to be "super active," said Montanna in an interview with People, so he needed something to rekindle his spirits: a puppy.

Craig, who was 70 years old at the time, didn't like the idea of a new dog at all, however, and repeatedly replied that he was "not ready" for it. However, his daughters knew they had to force their father's hand, or else he would stall forever, and so they surprised him with the puppy.

"We were nervous he'd feel overwhelmed with the responsibility the day we surprised him, but we knew we had enough support to make it happen,” she says, noting that she and her sister live just a few streets away and have remained closely involved ever since.

“[The TikTok video] just had me reflecting on the last three years with her and how it really was the best decision we could’ve made for him," she said. "She brought so much life back into him."

Dozer and Craig are now very closely bonded. It is impossible for him and his daughters to imagine life without the pooch.

"So many elderly people don't have that same luxury and, unfortunately, reach a point where they can't have dogs anymore – which is especially heartbreaking, because they're incredibly healing," she adds."Even though his children are grown, and he lives alone, he still has a strong sense of purpose in his everyday life."

Apparently, the exuberant dog motivates him every morning to get up, exercise, and watch the sunrise. The now-grown Dozer also loves to "help" his dad with DIY home projects, digging in the yard next to Craig and tagging along on trips to the hardware store.

"And he's never alone. You saved him, Dozer girl," reads the final onscreen text of the video.