Kim Eicher was shocked when she says she saw Jake, her neighbor's elderly German Shepard/Lab mix, chained for three days, lying on the ground unable to move, and struggling just to raise his head.

"I had to do something," Kim told INSIDE EDITION. "It was killing me to see that dog lie there like that."

Kim, who lives outside Altoona, Pa., says the owners weren't home, so she called the local Humane Society and left a message. But feeling time was of the essence, Kim then called in local animal rights activist Tammy Grimes, who came immediately equipped with her video camera.

"When we got there, we took our first picture from the road and we actually thought he already died," Grimes recalled.

Grimes then took matters into her own hands, and walked onto private property to save Jake. She took him off his leash, gingerly lifted him into her van, and then took him to a local vet, who described the dog as lethargic, severely dehydrated and in pain.

Then, instead of returning Jake, Grimes took the dog to an undisclosed location and is now refusing to return him to his rightful owners.

"When a dog is dying, it's close to death, it's suffering, somebody has to help the dog. I happen to be the only one willing to do it," she said.

Jake's owners, Steve and Lori Arnold, who have other dogs, came home to find Jake missing. They tracked down Grimes, who was promptly arrested for trespassing and theft. She still refuses to tell the Arnolds where their dog is.

The Arnolds admit Jake is old and suffering from arthritis and say they were about to have him put to sleep. But they deny he was lying on the ground for three days, and also deny that he was being neglected.

Tammy Grimes says Jake has seen two vets while in hiding and is doing better. The Arnolds are outraged that she refuses to return their dog, and think she should go to jail. Grimes says, "I'd rather spend my life in jail than give a dog back to someone who would just put him back on the end of a chain and let him die there."

Grimes has a court appearance set for Thursday where she faces the possibility of fines and probation.

Steve and Lori Arnold say (we are not making this up) "Jake was a member of our family."