The story follows Travis Coates, a young boy who reluctantly accepts taking in an old stray dog named Old Yeller to help his family on their farm in 1860s Texas. Despite their initial conflicts, Travis and Old Yeller form a strong bond. However, as time passes, it becomes evident that Yeller is aging and becoming a threat to the family due to his aggression towards strangers and wild animals.
The Coates family faces a dilemma; Travis is hesitant to put down Yeller because of their close friendship, while his parents know it is necessary for the safety of Travis, his brother Arliss, and the entire family. Ultimately, through the influence of his father and after witnessing Yeller attacking a rabid wolf, Travis must make a painful decision to shoot Old Yeller to protect his family from any potential harm.
Ultimately, Travis learns valuable lessons about loss, the circle of life, and the sacrifices sometimes required to do what is necessary for the safety and well-being of family and community. "Old Yeller" emphasizes the balance between love and duty, showing the growth and maturity of Travis as he comes to understand the complexities of both life and death in the harsh realities of their frontier lives.