  Understanding the mechanisms of qubit decoherence is a crucial prerequisite
for improving the qubit performance. In this work we discuss the effects of
residual Bogolyubov quasiparticles in Schr\"odinger cat qubits, either of the
dissipative or Kerr type. The major difference from previous studies of
quasiparticles in superconducting qubits is that the Schr\"odinger cat qubits
are operated under non-equilibrium conditions. Indeed, an external microwave
drive is needed to stabilize "cat states", which are superpositions of coherent
degenerate eigenstates of an effective stationary Lindbladian in the rotating
frame. We present a microscopic derivation of the master equation for cat
qubits and express the effect of the quasiparticles as dissipators acting on
the density matrix of the cat qubit. This enables us to determine the
conditions under which the quasiparticles give a substantial contribution to
the qubit errors.
