Dwight Howard's Dog Killed After Alleged Hit-and-Run, Asks Fans For Help

Dwight Howard is mourning the loss of his beloved dog, Sunday ... saying his companion was tragically killed in an alleged hit-and-run over the weekend.

The NBA center shared the sad news with his Instagram followers on Wednesday, posting several photos and videos of the good times with his Belgian Malinois.

Howard -- now playing in the BIG3 league after 18 NBA seasons -- said Sunday lost her life on June 18 in Suwanee, Georgia, after she was allegedly struck by a car that didn't stop.

Now, he's asking for the public's help.

"I need answers," Howard continued, "and I won't stop searching until I find out what happened to my beautiful Sunday."

The former NBA champion reflected on how much Sunday meant to him ... and how she was more than just his pet.

"You were my peace. My protector. A reminder of everything beautiful and calm, just like those early Sunday mornings," Howard said.

"You were joy. You were warmth. You were my girl. And you life was cut short too soon."

Howard's fans paid their respects in the comments ... one writing, "My condolences, brother. Sunday was a beautiful dog. May you find the answers and have peace."