 While the original title, "Trailing the Killer" isn t a misnomer, it was a bit misleading since the "trailer" is a dog named Caesar and the killer is a mountain lion, aka as a cougar or puma the narrator was quick to point out. But the makers also pointed out that Caesar "is the most intelligent dog actor since Rin-Tin-Tin" which probably lured a few Rin-Tin-Tin fans with a show-me attitude. Caesar prowls around the woods of the Northwest, dispatches a rattlesnake, visits his she-wolf mate and their pups, pauses to watch the dainty habits of a raccoon personally washing every morsel of food before eating it---and that raccoon had enough food to use up several minutes of running time---and then saves sheepherder Pierre (Francis McDonald) from getting et up by one mean mountain lion. Rin-Tin-Tin he ain t, but then who was? Commonwealth changed the title to "Call of the Wilderness" when they acquired it for 16mm rental to the school market.