[fujiuji]

According to one game official in southern Africa whom I spoke with directly, the main issue preventing gov't sanctioned dehorning from being a successful is (1) it's dangerous and expensive to track and sedate the animals, and (2) poachers spend time tracking a "hornless" rhino and, upon locating it, kill it anyway.

While [in the poacher's mind] this sends a message to game officials, the poacher is also able to recover about 2 inches of keratin, being that about 2 inches must be left behind in order to "safely" dehorn the animal.