Feline Herpesvirus and Upper Respiratory Welfare

Feline herpesvirus (FHV-1) is a major cause of chronic upper respiratory disease in cats, causing repeated painful flare-ups that require long-term welfare management.

Key Facts

FHV-1 infects over 90% of cats worldwide; most become latent carriers after initial infection
Stress triggers viral reactivation, causing recurrent episodes of sneezing, nasal discharge, and eye ulcers
Corneal ulcers from FHV-1 are extremely painful and can cause permanent scarring and vision loss
L-lysine supplementation was historically recommended but evidence for efficacy is now considered weak to absent
Antiviral medications including famciclovir reduce viral replication and are more effective for severe cases
Vaccination against FHV-1 does not prevent infection but reduces severity of clinical signs
Multi-cat households and shelters have highest rates of FHV-1 transmission and stress-triggered recurrence

Welfare Considerations

Cats with active FHV-1 episodes experience painful corneal ulceration, nasal congestion affecting their ability to smell and therefore eat, and general malaise. Chronic carriers suffer repeated welfare impacts throughout their lives, with stress — including rehoming, new animals, or environmental changes — reliably triggering flares. Shelter cats are disproportionately affected due to the combined stress of rehoming and exposure to new infections. Minimising stress, maintaining vaccination, and prompt treatment of flares with appropriate antivirals are the core welfare management strategies.

What You Can Do

Vaccinate your cat against FHV-1 as part of their core vaccination schedule
Minimise stressors for cats known to have FHV-1 history, including gradual introductions of new pets
Seek veterinary attention promptly for eye discharge or squinting — corneal ulcers need rapid treatment
Use synthetic feline pheromone diffusers during periods of anticipated stress in FHV-1-positive cats
Ask your vet about famciclovir if your cat has severe or frequent FHV-1 flare-ups