Screaming at a toddler not to touch something hot can be effective, sometimes, but not nearly as effective, long term, as allowing that curious mind to experience pain. The same is true of dogs, although they seem to have slightly more built-in survivorship skills than toddlers do, with one exception I can think of, dogs and porcupines. I cannot tell you how many times I have pulled porcupine quills from the muzzle, nose and face of the same dogs. They never seem to learn.
Maybe it’s the chase. Rabbits, squirrels, all those creatures that run and rarely get caught are a source of pleasure, dogs love the pleasure of the chase. Porcupines are disdainful. They scurry, but not quite fast enough to avoid the catch. Maybe they enjoy the reverse chase, knowing they will prevail.
Roger was a Boxer dog who never learned. The first time I saw him his head was as big as a soccer ball, filled with porcupine quills and swollen with inflammation. After anesthetizing the poor guy I spent almost two hours laboriously pulling quills, one at a time, out of him. I saw him at least three more time, maybe more, not nearly as loaded with quills, but obviously not hurt enough to learn, or maybe he had ADD. He was not the only dog I encountered with a similar problem when it came to porcupines.
The same phenomenon does not seem to exist when it comes to Cholla cactus, called the jumping cactus. During our recent travels, my dog Charlize knew to avoid getting close enough to that troublesome plant to experience it and I don’t recall treating the same dog more than once for a Cholla encounter. Charlize does love to chase small creatures. She has come amazingly close but has yet to capture one, but we haven’t run into a porcupine,…yet.