  We investigate, in the framework of perturbation theory at finite $N_s$, the
effectiveness of improved gauge actions in suppressing the chiral violations of
domain-wall fermions. Our calculations show substantial reductions of the
residual mass when it is compared at the same value of the gauge coupling, the
largest suppression being obtained when the DBW2 action is used. Similar
effects can also be observed for a power-divergent mixing coefficient which is
chirally suppressed. No significant reduction instead can be seen in the case
of the difference between the vector and axial-vector renormalization constants
when improved gauge actions are used in place of the plaquette action. We also
find that one-loop perturbation theory is not an adequate tool to carry out
comparisons at the same energy scale (of about 2 GeV), and in fact in this case
even an enhancement of the chiral violations is frequently obtained.
