Cat Feline Herpesvirus: Managing a Lifelong Respiratory Condition

Feline herpesvirus (FHV-1) is one of the most common causes of respiratory disease in cats. Understanding its lifelong nature enables welfare-centred long-term management.

Key Facts

Feline herpesvirus-1 is a leading cause of feline upper respiratory tract disease (cat flu)
Like all herpesviruses, FHV-1 establishes lifelong latent infection — cats remain carriers after initial recovery
Stress, illness, and corticosteroid administration can trigger viral reactivation and recurrent symptoms
Symptoms include sneezing, nasal discharge, conjunctivitis, and in severe cases corneal ulceration
Lysine supplementation was historically recommended but current evidence does not support its use
L-lysine is no longer recommended; instead, managing stress and supporting immune health is advised

Welfare Considerations

FHV-1 carriers manage a lifelong condition that flares under stress. The welfare implications are twofold: acute welfare impact during flare-ups (sneezing, eye discharge, occasionally severe corneal ulceration) and the chronic welfare risk of the unpredictability of flare-ups. Managing carrier cats focuses on stress reduction — the most important trigger for reactivation. Multi-cat household conflict, environmental changes, and illness are common triggers that can be partially managed through environmental modification and stress-reduction strategies. Antiviral medication (famciclovir) is effective during severe flare-ups but requires veterinary guidance. Welfare-centred management treats FHV-1 as a chronic condition requiring ongoing attention.

What You Can Do

Minimise stress in FHV-1 carrier cats — stress is the primary trigger for viral reactivation
Maintain current vaccination against FHV-1 — vaccine does not eliminate infection but reduces severity of reactivation
Seek veterinary attention promptly for corneal signs — corneal ulceration from herpesvirus can threaten vision
Ask your vet about antiviral medication (famciclovir) for severe or persistent flare-ups
Avoid the use of corticosteroids in FHV-1 carriers unless essential — steroids trigger reactivation