  We address the role of correlations between spin and charge degrees of
freedom on the dynamical properties of ferromagnetic systems governed by the
magnetic exchange interaction between itinerant and localized spins. For this
we introduce a general theory that treats quantum fluctuations beyond the
Random Phase Approximation based on a correlation expansion of the Green's
function equations of motion. We calculate the spin susceptibility, spin--wave
excitation spectrum, and magnetization precession damping. We find that
correlations strongly affect the magnitude and carrier concentration dependence
of the spin stiffness and magnetization Gilbert damping.
