  Recent observations suggest that Carina and other nearby dwarf spheroidal
galaxies are surrounded by unbound stars tidally stripped by the Milky Way. We
run high-resolution N-Body simulations of dwarf galaxies orbiting within the
Milky Way halo to determine if such observations can be explained with dark
matter potentials as those implied by current structure formation models. We
show that tidal forces acting on dwarfs with constant density cores or with
cuspy profiles having a low concentration parameter ($c < 5$) lead to flat
outer stellar density profiles like that of Carina for a variety of orbital
configurations. On the contrary, it is more difficult to remove stars from
cuspy dark matter halos with concentrations as high as predicted by CDM models
at the mass scale of dwarf galaxies ($c \simgt 10$) and the data can only be
reproduced assuming nearly radial orbits. Our simulations show that Carina is
losing mass at a fractional rate $< 0.1$ Gyr$^{-1}$ and its mass-to-light ratio
could be inflated by at most a factor of 2 due to unbound stars projected along
the line of sight. We follow the evolution of the tidal debris within a
triaxial clumpy cold dark matter Milky Way halo which causes differential
precession and small scale heating of the stellar streams. This renders their
use as a dynamical tracer of the Galactic potential practically useless, but
does provide a novel test of the nature of the dark matter. Models with warm
dark matter (WDM) or fluid dark matter (FDM) produce dwarf halos with lower
central densities than CDM and would be consistent with the observed tidal
tails even for orbits with eccentricities as low as indicated by current data
on nearby dwarf spheroidals. Galactic halos in FDM are smooth and spherical and
would be favored by the detection of coherent streams.
