The present invention relates to the field of animal health and in particular of Equine Herpes Viruses (EHV) wherein the gene encoding the protein gM is absent, and which is free of heterologous elements. Further aspects of the invention relate to pharmaceutical compositions comprising said viruses, uses thereof, and methods for the prophylaxis and treatment of EHV infections. The invention also relates to pharmaceutical compositions comprising the combination of EHV-1 and EHV-4 viruses wherein the gene encoding the protein gM is absent and which is free of heterologous elements.
