  We prove that the subgroup zeta function and the normal zeta function of a
finitely generated virtually nilpotent group are finite sums of Euler products
of cone integrals over $\mathbb{Q}$ and we deduce from this that they have
rational abscissa of convergence and some meromorphic continuation. We also
define Mal'cev completions of a finitely generated virtually nilpotent group
and we prove that the subgroup growth and the normal subgroup growth of the
latter are invariants of its $\mathbb{Q}$-Mal'cev completion.
