The Underneath by Kathi Appelt
A small abandoned cat finds her way to a lonely, howling hound deep in the backwaters of the bayou. She finds herself drawn in a way that could not be conceived by most to the place where the hound was.
The hound was lonely, chained for days to the porch of a dilapidated house that the cat found everything there was some how wrong. She should leave this place, walk away it couldn't be safe for her or her kittens about to be born. Then she rounded the corner and found the dog whose song she could not resist. She knew the answer to the song that he sang. Without fear she walked up to the Hound and rubbed herself against his legs.
The Hound was much surprised after all this time that someone was here who understood the song. Ranger love the Calico Cat right off. He pointed out to her how she was in much danger from the man "Gar Face" who lived in the house, who owned the gun. And so together they curled up underneath the porch. At last Ranger has found a friend.