"He's being told that this is a doggy megaphone so that his bark, as loud as it already is, resonates even more loudly across the neighborhood to keep the hooligans away. Not that it is really to keep him from biting himself as he is being treated for a bacterial infection."
This is not unlike the time when I was three when my parents told me my bunny, Snowy, ran away to be with her family. I believed this was true — and even embellished the story to include Snowy having tons of babies — until the age of 12, when I overheard my mom telling someone about the time our neighbor's dog murdered my rabbit.
Nor is it unlike the time they told my brother that it's not gross to have back hair. Sorry, Kyle. It is gross.