A friend told me when he was changing his oil last night, the pan was sitting out for a while. He spotted his dog walking out of the garage with oil dripping from his mouth and nose. There was a trail of drips from the dog back to the oil pan. He figures the dog thought is smelled pretty good and so gave it a taste. Probably never do that again. I must admit, I do like the smell of used oil, which is just one more reason to change it myself.