Recent studies show the possibility of the formation of fairly regular and global spiral patterns in dwarf galaxies (dS type). Our sample of observed dwarf objects of this class also includes galaxies with a central stellar bar. The analysis of the observational data provides a small rotation velocity and a small disk component mass for dS galaxies, which is in poor agreement with the spiral structure generation mechanism in isolated dwarfs due to the development of disk gravitational instability. Numerical simulation of the stellar–gaseous disks self-consistent dynamics imposes restrictions on the stellar disk thickness and the maximum gas rotation velocity, at which the gravitational mechanism of spiral formation can still be effective.