An equation set describing the evolution of the integrals of motion of
solitons, induced by relaxation processes of both a relativistic and
exchange nature is obtained within the framework of the phenomenologic
al theory. Two-parameter one-dimensional ferromagnetic and antiferroma
gnetic solitons and two- and three-dimensional ferromagnetic precessio
n solitons are analyzed. The corresponding integral curves are plotted
, and the time dependences of the soliton parameters at various relaxa
tion stages are discussed.