Infectious rhinotracheitis is a disease of the upper respiratory system sustained by feline herpesvirus type 1 (FHV-1), a very widespread and contagious virus. It is often associated with feline caliciviruses in feline upper respiratory tract infections. It is transmitted by direct contact with oral, conjunctival and nasal secretions that an infected cat eliminates already after 24 hours from the infection and for about 3 weeks. Symptoms include acute rhinitis and conjunctivitis, corneal ulcers, fever, depression and loss of appetite, pneumonia with fatal outcome is possible, especially in young cats. Generally the disease resolves in 2-3 weeks, but the virus remains latent giving the cat the status of carrier for life with intermittent elimination of the virus due to various stress factors that can lead to relapses.

Feline herpesvirus is more common in feline communities: catteries, shelters, colonies.

Vaccination provides effective protection: it helps reduce the severity of the disease and limits the occurrence of relapses.