  We have extended staggered chiral perturbation theory to O(a^2 p^2), O(a^4),
and O(a^2 m), the orders necessary for a full next-to-leading order calculation
of pseudo-Goldstone boson masses and decay constants including taste-symmetry
violations. We present predictions relating SO(4) taste-breaking splittings in
masses, pseudoscalar decay constants, and dispersion relations. These can be
used to test the fourth-root trick.
