  We analyze the dynamical behavior of a quasi-isotropic Universe in the
presence of a cosmological fluid endowed with bulk viscosity. We express the
viscosity coefficient as a power-law of the fluid energy density:
$\zeta=\zeta_0\epsilon^{s}$. Then we fix $s=1/2$ as the only case in which
viscosity plays a significant role in the singularity physics but does not
dominate the Universe dynamics (as requested by its microscopic perturbative
origin). The parameter $\zeta_0$ is left free to define the intensity of the
viscous effects.
  Following the spirit of the work by E.M. Lifshitz and I.M. Khalatnikov on the
quasi-isotropic solution, we analyze both Einstein and hydrodynamic equations
up to first and second order in time. As a result, we get a power-law solution
existing only in correspondence to a restricted domain of $\zeta_0$.
