From my own experiences, yes.
When I was younger and I owned a Dinkie Dino, my little sister gnawed the buttons off during her teething phase, and I removed them completely. I was using a pencil directly on the board (similar to when someone debugs a v3).
But be warned that using that after a length of time will mean that it gathers the graphite, and will probably stop working. I don't really know, though. I gave up on the pet before this happened, but, makes sense.