There is a very consistent naming scheme for Dilbert characters:
Dog -> Dogbert
Cat -> Catbert
Rat -> Ratbert
Mom -> Dilmom. Wait, what? Why is it not Mombert as wintermouse suggests? I think that neither Mombert or Dilmom have appeared in the comic itself, so these are names given only by the reader comminity (correct if I'm wrong). Or maybe this seems illogical only to us rodents? :D