Cat Conjunctivitis and FHV-1: Why Eye Infections Return

Key takeaway: Conjunctivitis in cats often keeps coming back because it is caused by Feline Herpesvirus (FHV-1), a lifelong virus that stays in the body and flares up during stress. You cannot clear the virus, but you can reduce and manage flare-ups with your veterinarian, so most cats live comfortably with fewer eye problems over time.

If your cat's red, weepy eyes seem to heal and then return weeks later, you are not doing anything wrong. You are most likely dealing with a virus that never fully leaves. Let us walk through why this happens and what you can actually do about it.

A cat resting comfortably at home.

What is conjunctivitis in cats?

Conjunctivitis in cats is inflammation of the conjunctiva, the thin pink tissue that lines the eyelids and covers the white of the eye. When it is inflamed, the eye looks red, swollen, and watery, and your cat may squint or hold the eye partly closed.

It is one of the most common eye problems seen in cats of every age. In many cats it affects one eye first and then the other.

Common signs include:

• Redness or a pink, swollen eye lining

• Watery, cloudy, or yellow eye discharge

• Squinting or blinking a lot

• A partly closed eye or pawing at the face

• Sneezing or a runny nose at the same time

The last point matters. When eye signs come with sneezing and nasal discharge, a virus is often behind it.

Why does my cat's eye infection keep coming back?

Recurring eye infections in cats are most often caused by Feline Herpesvirus (FHV-1), a lifelong virus that hides in the nerves and reactivates during stress. Once a cat is infected, FHV-1 stays in the body for life, so the same eye can flare again and again even after it looks fully healed.

This is the single most important thing for a Pawrent to understand. A returning infection usually does not mean the first treatment failed. It means the underlying virus woke up again.

Feline Herpesvirus (FHV-1) is also called feline viral rhinotracheitis, or simply "cat flu." It is a leading cause of upper respiratory infection and of repeat eye and breathing flare-ups in cats.

Flare-ups are commonly triggered by:

• Stress from a new home, new pet, travel, or boarding

• A new litter of kittens or a busy multi-cat household

• Other illnesses that lower the immune system

• Changes in routine or environment

Because stress is the main trigger, calmer cats tend to have calmer eyes.

How does Feline Herpesvirus (FHV-1) affect a cat's eyes?

Feline Herpesvirus (FHV-1) attacks the surface tissues of the eye and the upper airway, which is why it causes conjunctivitis, eye discharge, and sneezing together. In some cats the virus also damages the cornea, the clear front window of the eye, leading to painful corneal ulcers.

Typical eye and respiratory signs of FHV-1 include sneezing, nasal discharge, watery or gooey eye discharge, squinting, conjunctivitis, and sometimes corneal ulcers. A few cats also develop mouth ulcers.

When an ulcer forms, the eye becomes very sore and your cat may keep it tightly shut. This is a situation for a same-day veterinary visit, not home waiting.

Kittens and young cats often show the most dramatic first infection, with both eyes gummed shut and heavy sneezing. Adult cats more often show milder, repeating flare-ups in one eye.

Is it Feline Herpesvirus (FHV-1) or Feline Calicivirus (FCV)?

Feline Herpesvirus (FHV-1) and Feline Calicivirus (FCV) are two different viruses that both cause "cat flu," but they tend to hit different areas. FHV-1 is the bigger cause of eye disease and corneal ulcers, while Feline Calicivirus (FCV) is more strongly linked to mouth ulcers, drooling, and painful gum inflammation.

They can look similar early on, and a cat can even carry both. Only your veterinarian can tell them apart with an exam and, when needed, testing.

Feature	Feline Herpesvirus (FHV-1)	Feline Calicivirus (FCV)
Main eye signs	Conjunctivitis, corneal ulcers, heavy eye discharge	Milder, less common eye signs
Mouth signs	Sometimes mouth ulcers	Often mouth ulcers, gum and tongue inflammation
Course	Lifelong, flares with stress	Can persist, especially with gum disease
Typical antiviral a vet may prescribe	Famciclovir	Veterinarian-prescribed antiviral therapy

If mouth ulcers and drooling are the bigger problem, the picture may point more toward FCV. You can read one family's experience in this account of how a cat recovered from oral ulcers linked to FCV.

How is Feline Herpesvirus (FHV-1) conjunctivitis diagnosed?

Feline Herpesvirus (FHV-1) conjunctivitis is diagnosed by your veterinarian based on the pattern of signs, an eye exam, and sometimes specific tests. There is no home test, so a proper diagnosis always starts at the clinic.

Your veterinarian will usually:

1. Examine both eyes and check for discharge, redness, and swelling.

2. Use a fluorescein stain to look for corneal ulcers, which change management.

3. Ask about sneezing, stress, vaccination history, and past flare-ups.

4. Recommend further testing if the case is severe, one-sided, or not improving.

This matters because not every red eye is a virus. Injuries, foreign objects, and other infections can look the same, and each needs different care.

What is the treatment for cat eye discharge from FHV-1?

Treatment for cat eye discharge from Feline Herpesvirus (FHV-1) focuses on easing flare-ups, protecting the eye, and reducing how often the virus returns, because the virus itself cannot be removed. Care is always guided by your veterinarian and matched to how severe the signs are.

Depending on the case, a veterinarian may recommend:

• Gentle cleaning of the eyes to remove discharge

• Eye medications to soothe inflammation and protect the cornea

• An antiviral such as famciclovir, which is a medicine a veterinarian may prescribe for FHV-1

• Antibiotics only when a secondary bacterial infection is present

• Stress reduction and good nutrition to lower flare-up frequency

It is important to be clear on one point. Antibiotics do not treat the virus itself. They only address secondary bacterial infections that can ride along with a viral flare-up.

The famciclovir-based antiviral in the BasmiFIP family is called HerpX. HerpX contains famciclovir and does not contain GS-441524 or EIDD-1931, and any decision to use it, along with the right amount, is something only your veterinarian can determine for your cat.

Can Feline Herpesvirus (FHV-1) be cured?

No. Feline Herpesvirus (FHV-1) cannot be cleared or eliminated, because it is a lifelong infection that stays in the body even between flare-ups. The realistic and hopeful goal is control, which means fewer flare-ups, milder signs, and a comfortable cat.

Many cats with FHV-1 go on to live full, happy lives once their flare-ups are well managed. Please be cautious of any product that claims to remove the virus completely, because that is not how this virus works.

How can I prevent recurring cat eye infections at home?

You can reduce recurring cat eye infections from Feline Herpesvirus (FHV-1) by lowering stress, keeping vaccinations current with your veterinarian, and supporting general health so the virus reactivates less often. You cannot stop every flare-up, but you can make them rarer and milder.

Practical steps for a Pawrent at home:

1. Keep a calm, predictable routine, especially in multi-cat homes.

2. Introduce new cats, people, or changes slowly.

3. Keep the eyes clean by wiping away discharge with a soft, damp cloth, using a fresh section for each eye.

4. Feed a good-quality diet and keep fresh water available.

5. Stay on schedule with vaccinations and check-ups as your veterinarian advises.

6. Act early at the first sign of squinting or discharge instead of waiting.

Early action is the theme that repeats in successful cases. The sooner a flare-up is managed, the less damage it usually does.

When should I see a vet for cat conjunctivitis?

You should see a veterinarian for cat conjunctivitis whenever the eye is painful, cloudy, tightly closed, or not improving within a day or two, and always if there is a coloured discharge or your cat stops eating. A squinting, sore eye can mean a corneal ulcer, which needs prompt care.

Contact your veterinarian right away if you notice:

• An eye held completely shut or clearly painful

• Cloudiness or a visible spot on the surface of the eye

• Thick yellow or green discharge

• Signs that spread from one eye to both, plus sneezing

• A kitten with eyes gummed shut, or any cat that is not eating

When in doubt, it is always safer to have the eye checked. Eyes are delicate, and a short delay can turn a mild flare-up into a lasting problem.

FHV-1 flare-ups can also overlap with other feline infections, and Indian clinics are increasingly experienced at telling these apart. You can see how vets approach complex viral cases in these lessons from Indian veterinary clinics.

FAQ

Why does my cat keep getting conjunctivitis in the same eye?

Repeated conjunctivitis in the same eye is usually caused by Feline Herpesvirus (FHV-1), which stays in the nerves near that eye for life and reactivates during stress or illness. Managing stress and treating flare-ups early with your veterinarian can make these episodes less frequent and milder.

Is feline herpesvirus eye infection contagious to other cats?

Yes, Feline Herpesvirus (FHV-1) spreads easily between cats through discharge from the eyes and nose, shared bowls, and close contact. It does not infect humans or dogs, but you should keep an actively flaring cat separated from other cats and wash your hands after handling them.

Can I treat my cat's eye discharge at home without a vet?

You can gently wipe away discharge with a soft, damp cloth, but you should not use human eye drops or leftover medications, because the wrong product can worsen a corneal ulcer. Any medicated eye treatment or antiviral for FHV-1 should be chosen and dosed by your veterinarian.

Will my cat have eye infections for the rest of its life?

Most cats with Feline Herpesvirus (FHV-1) will carry the virus for life, but that does not mean constant infections. With stress reduction, good care, and prompt treatment of flare-ups, many cats have only occasional, mild episodes and live comfortable, happy lives.

Does an antiviral help with FHV-1 conjunctivitis?

An antiviral such as famciclovir is a medicine a veterinarian may prescribe to help manage Feline Herpesvirus (FHV-1) flare-ups, alongside eye care and stress reduction. It supports control of flare-ups rather than removing the virus, so it works best as part of a plan your veterinarian designs for your cat.

If your cat's eyes keep flaring and you want to understand your options, you do not have to figure it out alone. Talk with your own veterinarian about a management plan, and reach out to the BasmiFIP team in India to learn more about supportive antiviral care for feline viral infections. Every treatment decision stays with your veterinarian, who knows your cat best.