Viral Characteristics

Herpes Virion

Feline viral rhinotracheitis is caused by a virus called feline herpesvirus-1.  It is an alphaherpes virus, which means it is part of a subfamily of the genus Varicellovirus.  Feline herpesvirus shares a lot of similarities with canine herpesvirus-1 but they should be considered as separate entities.  Like all herpesviruses, this virus contains a double-stranded DNA genome and it is covered by an envelope.  Having an envelope makes a herpesvirus susceptible to inactivation by drying or by disinfectants such as soap.  Therefore, feline herpesvirus-1 relies on close contact to be transmitted from one cat to another as it is also unstable as an aerosol.   A key feature of this virus is that once it is contracted, it will always be present in the host either as a detectable infection or as a latent infection, where the virus takes up residence in the trigeminal ganglia (part of a cranial nerve found in the face), only producing clinical signs when reactivated.