  A number of recent studies indicates a significant amount of ionized gas in a
form of the hot gas halo around the Milky Way. The halo extends over the region
of 100 kpc and may be acountable for the missing baryon mass. In this paper we
calculate the contribution of the proposed halo to the dispersion measure (DM)
of the pulsars. The Navarro, Frenk & White (NFW), Maller & Bullock (MB) and
Feldmann, Hooper & Gnedin (FHG) density distibutions are considered for the gas
halo. The data set includes pulsars with the distance known independently from
the DM, e.g. pulsars in globular clusters, LMC, SMC and pulsars with known
parallax. The results exclude the NFW distribution for the hot gas, while the
more realistic MB and FHG models are compatible with the observed dispersion
measure.
