In the book, Old Yeller battles a rabid, loafer wolf. Travis is alerted to what Old Yeller is up against when his mother warns him about the mad wolf.

As he runs outside to help his mother and Lisbeth to safety, Travis sees Old Yeller wrestling with another animal. He describes the animal as a fierce and savage wolf. As Old Yeller fights bravely, he lets out a prolonged, savage yell, indicating that he will fight to the death to protect his human family.

Travis's mother tells him to get his gun to shoot down the wolf. To give himself light, he drops a live coal onto a pile of bear grass clumps. However, Travis is disappointed when he is unable to get a good shot at the wolf. At this point, the bodies of Old Yeller and the loafer wolf are entwined in a ferocious wrestle to the death.

Eventually, the tumbling stops. The wolf manages to get on top of Old Yeller and to lock his powerful jaws onto Old Yeller's neck. Knowing that Old Yeller will die if he does not shoot, Travis takes aim. After the shot, he thinks that he has killed both the loafer wolf and Old Yeller. However, Travis is relieved when Old Yeller lifts up his head and begins licking his hand. The chapter ends on a sad note: knowing that Old Yeller has been bitten by a rabid wolf, Travis shoots his beloved pet.