Same dog as had the bumps, they seem to be gone. I do think that was from digging as I haven't seen any in a while and we've been keeping her from digging.
Based on how old she was when we got her, we gave her the semi-arbitrary birthday of New Year's, so she's a year and a half. Generally she's got good tooth hygiene.
Her gums were really bloody for a couple days, we took everything away and they went from an angry red to a pink color, but now she's back at a red with blood and she doesn't have anything to chew on.