VACAVILLE (CBS13) — A Vacaville woman is pleading for justice in the tragic death of her puppy.

Vacaville police say 18-month old “Rex” was thrown out of a moving car along Eastbound I-80 Thursday night.

The puppy’s back legs were bound.

Now there’s a reward of just over a thousand dollars leading to the arrest of whoever did it.

“I absolutely loved him dearly and I miss him so much, it just left a real hole in my life,” said an emotional Debra Ferrara.

Emptiness now hangs over Ferrara, her four-legged sidekick “Rex” is no longer by her side.

“He was my little companion all the time, he rode on the console on the car, we have taken a few trips to Idaho to see my sister,  and he rides along,” Ferrara said.

The two were inseparable until last Thursday. Ferrar had to go to a funeral and she says it was too warm to keep Rex in the car.

“I said, ‘I’m sorry Rex, but you’ve gotta stay home,’” Ferrara said.

That was the last time she would see her 18-month-old puppy.

Rex somehow found his way out of his home and took off.

Ferrara came home to the shock of her life.

“I was calling and calling, realized all the leashes were on the hanger but there was no Rex,” Ferrara added.

Rex was picked up by a blue Toyota Prius.

A couple told police they saw someone throw him out of the car window on eastbound Interstate 80 in Vacaville. The puppy’s back legs were tied.

“How could you do such a thing, an evil vile thing?” questioned Ferrara.

By the time the couple pulled over to rescue Rex, he had already been run over.

“It just broke my heart and I felt like we needed to do something to a stop to it before it happens to someone else,” said Susan Barbarick.

Barbarick is the founder of Pause 4 Paws, an animal rescue organization in Vacaville. She’s putting up a reward, hoping it will lead to the dog-napper.

“It can’t bring Rex back to Deb, but we hope at least to find those responsible and bring them to justice,” Barbarick said.

“I’ll never be able to replace him,” said Ferrara emotionally.

An unbreakable bond between a woman and her puppy, now fueling her quest to find the person who ripped her life apart.

“I hope he rots in hell, I hope he rots in hell,” was Ferrara’s message to the suspect.

Vacaville police are still searching for leads.