  In highly improved staggered quark (HISQ) simulations by the HPQCD, MILC, and
Fermilab Lattice collaborations, both the light quarks and the charm quark are
staggered. We extend chiral perturbation theory for staggered quarks to include
such all-staggered heavy-light mesons. We assume that the heavy quark action is
sufficiently improved that we may take $a m_Q <<1$ (where $m_Q$ is the heavy
quark mass), but also that $m_Q>>\Lambda_{QCD}$ so that a continuum heavy quark
expansion is appropriate. We develop this effective chiral theory through
next-to-leading order, and use it to study the pattern of taste splittings in
the heavy-light meson and to compute the leptonic decay constant of the
heavy-light meson to one-loop in the chiral expansion.
