Anomaly constraints on monopoles and dyons

Fermions with magnetic charges can contribute to anomalies. We derive the axial anomaly and gauge anomalies for monopoles and dyons, and find eight new gauge anomaly cancellation conditions in a general theory with both electric and magnetic charges. As a by-product, we also extend the Zwanziger two-potential formalism to include the theta parameter, and elaborate on the condition for CP invariance in theories with fermionic dyons.