Non-local gauge-invariant regularization and Ward identity anomalies

A gauge-invariant regularization of a massive spinor field interacting with external scalar, pseudoscalar, vector and axial fields is found. It is based on epsilon separating the vertices in the total Lagrangian. Rules for its use are deduced and Ward identities are written. Anomalies, present only in the divergence of the axial current, are interpreted as the high-energy contribution of the integrals associated with some loops. They can be computed in a simple way, confirming Bardeen's result. (8 refs).