  In previous publications we have analyzed the strong and electromagnetic
decays of heavy mesons and heavy baryons in a formalism which incorporates
heavy-quark and chiral symmetries. There are two possible symmetry-breaking
effects on the chiral dynamics of heavy hadrons: the finite-mass effects from
light quarks and the $1/ m_Q$ corrections from heavy quarks. In the present
paper, chiral-symmetry-breaking effects are studied and applications to various
strong and radiative decays of heavy hadrons are illustrated. SU(3) violations
induced by chiral loops in the radiative decays of charmed mesons and charmed
baryons are compared with those predicted by the constituent quark model. In
particular, available data for $D^*$ decays favor values of the parameters in
chiral perturbation theory which give predictions for $D^*$ decays close to the
quark model results except for the $D^{*+}_s$. Implications are discussed.
