LAS VEGAS — Judith Monarrez crumpled onto her kitchen floor and wept when the news arrived in an email: Gizmo, her pet dog missing for nine years, had been found alive.

Monarrez was 28 and living with her parents in 2015 when Gizmo, then 2 years old, slipped past a faulty gate in the backyard of their home in Las Vegas.

In the decade that followed, Monarrez, now 37, achieved personal milestones, including earning a master’s degree and starting a teaching career, all while searching for Gizmo.

Now, she was climbing into her car to drive across town to meet Gizmo at an animal hospital. Monarrez was later told that a woman had found the now 11-year-old dog and dropped him off at the vet, where they scanned his microchip, triggering the email notification that sent Monarrez to her knees, crying.

Within hours of receiving that email on July 17, Gizmo was back in his owner’s arms. Monarrez called it “a miracle.”

“Hindsight is 2020,” she said. “I’m so glad I registered his microchip.”

Their reunion came at the same time a new Las Vegas city ordinance requiring pet owners to microchip their cats and dogs is set to take effect Aug. 1.

Monarrez said Thursday that Gizmo’s first week back at home has brought mixed emotions.

She observed that their separation had changed Gizmo, the 8lb Chihuahua, who now feared shadows, heights, and birds, and walked with a limp. Monarrez noted severe eye infections and missing teeth.

“Even though he looked so different, when I looked in his eyes I knew immediately it was Gizmo,” Monarrez said, recalling the moment they were reunited at the vet’s office. “And as soon as I said his name, he tilted his head and he didn’t stop staring at me.”

While Monarrez and her parents can’t stop thinking about what Gizmo endured after he went missing, their focus now, she said, is on addressing his health issues and “showering him with all the love that we were holding onto for all those years.”