Why Stress Can Trigger Feline Herpesvirus Flare-Ups—and How to Help Your Cat

Your cat seems completely fine for months—then after a move, boarding stay, new pet or stressful week, the sneezing and watery eyes suddenly return.

For cats carrying feline herpesvirus type 1 (FHV-1), that pattern is not unusual. The virus can remain latent in the body and reactivate later, with stress being one of the best-recognised triggers.

What is feline herpesvirus?

Feline herpesvirus type 1, also called feline viral rhinotracheitis, is a common cause of upper respiratory disease in cats.

The Cornell Feline Health Center notes that cats can develop sneezing, eye or nasal discharge, conjunctivitis, fever and reduced appetite during active infection.

Once infected, many cats become lifelong carriers. The virus can remain inactive for long periods and then reactivate later.

Why can stress trigger a flare-up?

VCA Animal Hospitals explains that stress and illness can reactivate latent FHV-1. When this happens, a cat may again show respiratory signs and may also shed virus.

Cornell similarly notes that infected cats may periodically shed the virus, particularly when stressed.

Stress does not “create” herpesvirus. Instead, it can change the body's normal balance enough for a latent infection to become active again.

What kinds of stress can matter?

Every cat responds differently, but common flare-up situations include:

• moving house
• boarding or staying in a cattery
• bringing home a new pet
• a new baby or unfamiliar visitor
• surgery or another illness
• crowded living conditions
• major changes to routine
• conflict between cats in the same home

VCA specifically highlights moving, new pets and other major household changes as common stressors associated with recurrence.

What does an FHV-1 flare-up look like?

Typical signs can include sneezing, nasal congestion, clear or coloured nasal discharge, watery or inflamed eyes, conjunctivitis, squinting, reduced appetite, fever or lethargy.

Eye involvement is especially important. VCA notes that FHV-1 is a common cause of conjunctivitis in cats, and some cats experience recurrent ocular disease.

If your cat mainly has sneezing and nasal symptoms, our guide Why Does My Cat Keep Sneezing? explains other possible causes too.

Can you prevent every flare-up?

No. A cat that carries FHV-1 may still experience recurrence even with excellent care. The goal is to reduce avoidable stress, support general health and act early when symptoms become more significant.

7 ways to make stressful periods easier for your cat

1. Make changes gradually

When possible, introduce new pets, people, rooms or routines slowly rather than all at once.

2. Give your cat safe hiding places

Provide quiet spaces where your cat can retreat without being disturbed.

3. Keep food, water and litter resources predictable

Major changes to resource location can add unnecessary stress, particularly in multi-cat households.

4. Reduce competition between cats

Provide multiple feeding, water, litter and resting areas so one cat cannot easily block another.

5. Keep familiar smells during moves or boarding

A familiar blanket or bed can help preserve a sense of routine.

6. Support appetite and hydration

Respiratory congestion can reduce smell and appetite. If your cat eats less, offer palatable food and contact your veterinarian if intake remains poor.

7. Ask your vet about high-stress events

For cats with a history of severe recurrent FHV-1, your veterinarian may recommend a specific plan around boarding, surgery or other predictable stressors.

What role does vaccination play?

Vaccination does not guarantee that a cat will never become infected with FHV-1, but it remains an important part of prevention. Cornell notes that vaccination can significantly reduce disease severity and viral shedding.

What about L-lysine?

L-lysine has historically been recommended for cats with feline herpesvirus, but the evidence is controversial. Cornell notes that several studies have not found lysine supplementation effective and that some research suggests it may worsen signs or promote viral shedding.

For a more detailed look at this topic, see L-Lysine for Cats: Is One Ingredient Enough for Immune Support?.

Where does everyday immune support fit?

Stress management works best as part of a broader health routine: complete nutrition, vaccination, parasite prevention, sleep, stable routines and appropriate veterinary care.

Our guide How to Support Your Cat's Immune System Naturally covers those foundations in more detail.

MIHIJO Immunity Enhance is designed as daily nutritional support for normal immune function and overall wellness. It should not be viewed as a treatment for FHV-1 or as a replacement for vaccination or antiviral medication when prescribed.

When should you call the vet?

Seek veterinary advice if your cat has persistent or severe respiratory signs, eye pain, corneal changes, significant appetite loss, dehydration, marked lethargy or repeated flare-ups.

The bottom line

FHV-1 can remain latent for life, and stress is a well-recognised trigger for recurrence. You cannot control every flare-up, but you can reduce avoidable stress, maintain a predictable environment and seek veterinary help when symptoms are more than mild.

For a cat with recurring respiratory or eye signs, the goal is not simply “boosting immunity.” It is creating the conditions that help the whole cat stay stable.

Sources

• Cornell Feline Health Center — Respiratory Infections
• VCA Animal Hospitals — Feline Herpesvirus Infection
• VCA Animal Hospitals — Managing and Preventing Feline Herpesvirus
• VCA Animal Hospitals — Feline Herpes Viral Conjunctivitis

Disclaimer: This article provides general educational information only and is not a substitute for veterinary diagnosis, vaccination or treatment.