SPRINGFIELD, Ill. (WAND) - A dog was left to starve after his owners abandoned him in their own home.

The property's landlord, Shane Sullivan, said these tenants failed to pay rent for four months.

"Right now with the moratorium, landlords' hands are kind of tied," Sullivan said. "I  just wanted to check on the well-being of the property. I didn't know if she was living there or wasn't. I just noticed some mail on the front porch that had been sitting there for several days."

Sullivan said he sent several notices to the tenants and posted a notice of entry. Twenty-four hours later he entered the property. According to Sullivan, what he saw in the residence was a sight he will never forget.

"I saw feces, trash like the dog had been eating anything it could," Sullivan said. "It was just a mess."

In all the mess, Sullivan found a dog - 4-year-old Sii.

"[Sii] starved for quite sometime. It didn't happen overnight," Sullivan said. "There was no excuse for it. There was a lot of other options. I believe that dog was adopted less than a year ago."

Director of the Animal Protective League in Springfield, Deana Corbin, said Sii called APL home before he was adopted.

"Sii did come from APL," Corbin said. "He was here back in May. He was a super sweet dog, very loving, very happy and playful."

According to Corbin, the APL staff was devastated by the news.

"They've been given a second chance at life here, and we hope when they go to their forever home they'll live a happy, healthy life," Corbin said. "To see that was just shocking and heartbreaking to all of the staff."

Corbin said she wants to remind pet owners there are other options if they are struggling.

"We have a pet food bank," Corbin said. "People can come here and get free food from us."

Sullivan said upon finding Sii, he immediately contacted Springfield police. This case is still under investigation by Sangamon County Animal Control.

In Illinois, animal abuse cases can result in a felony charge if the abuse leads to the animal's death.

"It's sickening," Sullivan said. "This dog depended on someone he thought loved and cared for him to let him out, and I just can't imagine how that dog felt."