Glossary

Feline herpesvirus

A common virus that causes sneezing, eye inflammation and nasal discharge, and stays in the body for life, flaring up in times of stress.

Also called: FHV-1, feline viral rhinotracheitis, FVR, cat herpes

Feline herpesvirus type 1, or FHV-1, causes feline viral rhinotracheitis, one of the main forms of cat flu. It affects only cats and does not infect people or dogs. Kittens often catch it from their mother or from other cats in shelters and catteries.

Signs include frequent sneezing, a runny nose, watery or sticky eye discharge, red eyes and sometimes a fever and low appetite. The virus can also damage the surface of the eye, causing painful ulcers, and kittens can lose sight in severe cases. A cat that squints, keeps an eye closed or has a cloudy eye needs a vet soon.

After the first infection the virus usually stays dormant in the nerves for life. Stress, such as a move, a new pet or a boarding stay, can bring it back and make the cat shed virus again. Vaccination is part of the FVRCP combination and among the core vaccines. It does not stop infection but makes illness milder. Ask your vet about managing flare-ups, including eye care, and about keeping a calm routine for a cat prone to them.

Last reviewed November 7, 2026

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Related terms

Upper respiratory infection A contagious infection of the nose, throat and eyes that causes sneezing, discharge and a poor appetite, common in kittens and shelter cats. Feline calicivirus A common virus behind cat flu that causes sneezing, eye discharge and painful mouth ulcers, and sometimes severe illness. FVRCP vaccine The combination cat vaccine that protects against feline herpesvirus, calicivirus and panleukopenia. Core vaccines The vaccines vets recommend for every cat, as opposed to non-core vaccines chosen according to a cat's lifestyle and risk.