For whatever reason, my dad thought it would be cute to buy poor Heidi antlers for Christmas. (He also bought her treats, but those were little consolation at the time!) She just looks like she is enjoying it, doesn't she?!
Perhaps Bert felt badly that he got a nice coat for Christmas and Heidi got stuck with the antlers, so he started attacking the ears. He could have also thought they were a chew toy. One can never be sure.
I'm pretty sure some doggy ice cream would have been more appreciated. Next year, doggies!