I get the feeling that many people consider this movie "old fashioned". That's unfortunate. The story of people appreciating a dog's love and loyalty should always be considered first rate material. And in this case it was done by the master himself; Walt Disney. Who could not be captivated by Old Yeller's lovable face and smile. The well done story line took him from scoundrel to protector and companion. Granted, the scenes showing Old Yeller fighting off the animal "villains" had a somewhat unnatural look about them; but getting a herd of wild pigs, for example, to do what you want, can't be too easy. And Tommy Kirk really nailed it (the feeling of grief) in the scene where he put Old Yeller out of his misery.
Review of Old Yeller
