Feline Herpesvirus (FHV-1) in Cats: Symptoms and Care

Feline herpesvirus (FHV-1) is a lifelong viral infection and one of the leading causes of upper respiratory illness and recurring eye problems in cats. The most common signs are sneezing, runny eyes, squinting, and nasal discharge, often flaring during stress. There is no way to eliminate the virus, so care focuses on managing and reducing flare-ups with support from your veterinarian.

A cat resting comfortably at home.

What is feline herpesvirus (FHV-1) in cats?

Feline herpesvirus (FHV-1) is a common, highly contagious virus that causes upper respiratory infection and eye disease in cats, and it is also known as feline viral rhinotracheitis or "cat flu". It is a lifelong infection, which means once a cat is infected the virus stays in the body for life.

Many cats catch FHV-1 as kittens, often from their mother or from other cats in shelters, catteries, and multi-cat homes. After the first illness settles, the virus becomes dormant and can reactivate later.

This is why care for feline herpes is about managing flare-ups rather than clearing the virus. A cat can look completely healthy for months and then show symptoms again when stressed or unwell.

What are the symptoms of FHV-1 in cats?

The main symptoms of FHV-1 in cats are sneezing, nasal and eye discharge, squinting, conjunctivitis, and sometimes corneal ulcers or mouth ulcers. Signs often appear together and can range from mild to severe depending on the cat.

Here are the most common signs of a feline herpes infection to watch for:

• Frequent sneezing and a blocked or runny nose

• Watery or thick discharge from the eyes

• Squinting, blinking, or holding an eye partly closed

• Red, swollen conjunctiva (the tissue around the eye)

• Corneal ulcers, which are painful sores on the surface of the eye

• Reduced appetite, often because a blocked nose dulls the sense of smell

• Mild fever and low energy during a flare-up

Kittens and older cats tend to show stronger symptoms. In young kittens, severe eye involvement needs prompt veterinary attention to protect long-term vision.

Why does my cat have eye discharge with feline herpes?

Eye discharge is one of the most recognisable signs of feline herpesvirus because FHV-1 directly infects the tissues of the eye and the surrounding membranes. This inflammation, called conjunctivitis, makes the eyes water, redden, and produce discharge that can be clear, cloudy, or yellow-green when a secondary bacterial infection is present.

In more serious cases the virus damages the cornea and creates ulcers. These are painful and can cause heavy squinting, so any cat holding an eye shut or pawing at the face should be seen by a veterinarian.

If you are searching for cat eye discharge treatment, the safest first step is a veterinary eye exam. Some eye medicines that are fine for people or other conditions can worsen a herpes-related corneal ulcer, so never medicate a cat's eye without professional guidance.

What triggers feline herpesvirus flare-ups?

FHV-1 flare-ups are most often triggered by stress and by anything that lowers a cat's immune defences. Because the virus stays dormant in the body, these triggers can wake it up and bring symptoms back weeks, months, or years after the first infection.

Common triggers include:

1. Moving house, boarding, or travel

2. New pets, new people, or changes in the household

3. Other illnesses or surgery

4. Pregnancy and nursing in queens

5. Overcrowding in multi-cat homes and shelters

Reducing stress and keeping routines steady are practical ways to lower how often flare-ups happen. Good nutrition, clean living spaces, and gentle handling all help support a cat prone to feline herpes.

How is feline herpesvirus different from feline calicivirus?

Feline herpesvirus (FHV-1) and feline calicivirus (FCV) are two different viruses that both cause cat flu, but they affect cats in different ways and are managed with different products. FHV-1 tends to cause more eye and nasal signs, while FCV is strongly linked to mouth ulcers and oral disease.

The two are easy to confuse because they share respiratory symptoms and often circulate in the same environments. The table below sets out the key differences.

Feature	Feline herpesvirus (FHV-1)	Feline calicivirus (FCV)
Common signs	Sneezing, eye discharge, conjunctivitis, corneal ulcers	Mouth ulcers, drooling, oral pain, respiratory signs
Nature of infection	Lifelong, reactivates with stress	Can be shed for weeks to months, varies by cat
Antiviral line	HerpX (famciclovir)	CaliciX / CaliciX Max (EIDD-1931)
Focus of care	Managing recurring flare-ups	Managing oral and respiratory disease

If your cat's main problem is mouth ulcers or drooling rather than eye discharge, read more about feline calicivirus symptoms and vet care to compare the two. Your veterinarian can confirm which virus is involved, and sometimes both are present at once.

How is feline herpesvirus treated in cats?

Feline herpesvirus is treated by managing flare-ups, supporting the immune system, and using antiviral or supportive medicines chosen by your veterinarian, because the virus itself cannot be eliminated. Treatment aims to shorten and soften each episode and to protect the eyes.

Famciclovir is an antiviral that a veterinarian may prescribe for feline herpes. In the CureFIP range, the FHV-1 product line is called HerpX, and its active ingredient is famciclovir. HerpX does not contain GS-441524 or EIDD-1931, and dosing must always be set by your veterinarian rather than estimated at home.

Because the right dose depends on the individual cat, we do not publish HerpX dosing figures here. Your veterinarian will decide the strength, amount, and schedule based on your cat's weight, age, and symptoms.

Supportive care usually includes:

• Keeping the eyes and nose gently clean

• Managing secondary bacterial infection when your veterinarian prescribes antibiotics

• Encouraging eating with warm, aromatic food during a blocked-nose phase

• Reducing stress to lower the chance of the next flare-up

It is important to know that antibiotics do not act on FHV-1 itself. They only treat the secondary bacterial infections that can appear on top of a viral flare-up. For a fuller picture of what to expect from care in this region, see our guide to feline herpesvirus treatment in Australia.

Can feline herpesvirus be cured?

No, feline herpesvirus cannot be cleared or eliminated from the body, because FHV-1 is a lifelong infection that stays dormant between flare-ups. The realistic and honest goal is control, which means fewer and milder episodes and healthy, comfortable stretches in between.

At CureFIP we are clear about what the evidence shows and what it does not. There is no published success rate for feline herpes treatment, so any percentage claim about "clearing" the virus would be misleading. Care is measured by how well flare-ups are managed over your cat's lifetime.

The upside is that many cats with FHV-1 live full, happy lives. With steady routines, prompt attention to eye symptoms, and veterinary guidance, most flare-ups can be handled well.

How can Australian and New Zealand owners protect their cats?

Australian and New Zealand owners can protect their cats by keeping core vaccinations up to date, reducing stress, and acting quickly when eye or respiratory symptoms appear. Vaccination does not always prevent infection, but it helps reduce the severity of illness.

Practical steps that help include:

1. Follow your veterinarian's vaccination schedule, which typically covers both FHV-1 and FCV

2. Keep multi-cat homes clean and avoid overcrowding

3. Separate a sneezing cat from others during an active flare-up

4. Wash hands and food bowls to limit spread between cats

5. Book a veterinary visit early when you see eye discharge or squinting

Because FHV-1 and FCV are often bundled in the same vaccine, it is worth understanding what these vaccines do and do not cover. Our overview of the feline calicivirus vaccine in Australia explains the protection and the gaps.

As a network, CureFIP has supported more than 100,000 cats since 2019 across its treatment programs, and that experience shapes our transparent, veterinary-led approach to feline viral disease.

FAQ

Is feline herpesvirus contagious to other cats?

Yes, feline herpesvirus (FHV-1) is very contagious between cats, spreading through direct contact, shared bowls, and droplets from sneezing. It does not infect humans or dogs, so only other cats are at risk.

How long does a feline herpes flare-up last?

Most feline herpesvirus flare-ups last around one to two weeks, though corneal ulcers and severe cases can take longer and need closer veterinary care. If symptoms are not improving or the eye looks worse, contact your veterinarian promptly.

Can I treat my cat's eye discharge at home?

You can gently wipe away feline herpes eye discharge with a clean, damp cloth, but you should not use eye medicines without veterinary advice. Some products can worsen a herpes-related corneal ulcer, so a proper eye exam is the safest path to correct cat eye discharge treatment.

Does my cat need antibiotics for feline herpesvirus?

Antibiotics do not treat FHV-1 itself, because the virus is not a bacterium. Your veterinarian may still prescribe antibiotics if a secondary bacterial infection develops on top of the viral flare-up.

Will my cat always have feline herpes?

Yes, once a cat is infected with FHV-1 the virus stays for life and can reactivate during stress or illness. With good routines and veterinary support, most cats have long, comfortable periods between flare-ups.

If your cat is showing sneezing, eye discharge, or repeated flare-ups, the best next step is a conversation with people who understand feline viral disease. You can explore the CureFIP Oceania resources to learn more and then work with your own veterinarian on the right plan for your cat. Every treatment decision should be made with your veterinarian, who knows your cat's history best.