Abstract
We complete our study of non-Abelian gauge theories in the framework of the Epstein-Glaser approach to renormalization theory including in the model an arbitrary number of Dirac fermions. We consider the consistency of the model up to the third order of the perturbation theory. In the second order we obtain pure group theoretical relations expressing a representation property of the numerical coefficients appearing in the left- and right-handed components of the interaction, Lagrangian. In the third order of the perturbation theory we obtain the the condition of cancellation of the axial anomaly.