  We consider spin ice magnets (primarily, $\mathrm{Dy_2Ti_2O_7}$) in the
vicinity of their critical point on the $(H,T)$ plane. We find that the
longitudinal susceptibility diverges at the critical point, leading to the
behaviour qualitatively similar to the one which would result from non-zero
conductance of magnetic charges. We show that dynamics of critical fluctuations
belongs to the universality class of easy-axis ferroelectric and calculate
logarithmic corrections (within two-loop approximation) to the mean-field
critical behavior.
