Uveitis in Cats With FIP or FIV: What Owners Should Know

Name: Uveitis in Cats With FIP or FIV: What Owners Should Know
Creator: Dr. Zubair Khalid

By Dr. Zubair Khalid, DVM, MS, PhD · 2026-10-03

Uveitis in cats with FIP happens when the virus inflames the inner structures of the eye, and the same process can occur with FIV. Both viruses can trigger eye inflammation that is painful and sometimes the first sign owners notice. This article is educational and is not a substitute for veterinary diagnosis or treatment.

Quick Answer

Uveitis means inflammation inside the eye, most often the iris and ciliary body. It can affect one eye or both [1].
FIP and FIV are both listed among the common infectious causes of anterior uveitis in cats [1].
In one study of 118 cats with FIP, about 40% had eye abnormalities at diagnosis, most often anterior uveitis, keratic precipitates, and chorioretinitis [2].
Uveitis is often the only visible sign of a whole-body infection, so any red, squinting, or cloudy eye needs a vet exam [1].
Antiviral treatment for FIP has improved eye inflammation quickly in many cats, often within the first week [2].

What Uveitis Means in Plain Words

The uvea is the middle layer of the eye. It includes the iris (the colored part), the ciliary body (which makes fluid inside the eye), and the choroid (the layer behind the retina). When this tissue becomes inflamed, the condition is called uveitis.

Anterior uveitis, also called iridocyclitis, affects the front portion, the iris and ciliary body [1]. It happens often in cats. It may appear in one eye after trauma, eye parasites, or certain cancers, or in both eyes when a whole-body infection or immune disease is involved [1].

Uveitis is not a disease by itself. It is a reaction, and your veterinarian's job is to find what is driving it. Left untreated, the inflammation can damage the eye and affect vision [1].

Signs Owners Notice First

Cats hide discomfort well, so eye changes are often the clue that something systemic is wrong. Watch for:

Squinting or holding one eye closed
A protruding third eyelid (the pink membrane at the inner corner)
Red or bloodshot eyes
Cloudiness or a blue-gray haze over the cornea
A pupil that stays small or looks irregular
Sensitivity to light
Rubbing or pawing at the face
Bumping into things or seeming less sure of where it is jumping

In a study of kittens, FIP-associated uveitis was more often linked with corneal edema, an oddly shaped pupil, visible new blood vessels on the iris, a thickened or congested iris, adhesions between the iris and lens, and keratic precipitates (clumps of inflammatory cells stuck to the back of the cornea) [3]. Those kittens also had more severe corneal swelling than kittens with a milder, self-resolving uveitis [3].

If your cat's eyes look red or cloudy, this guide on bloodshot eyes, uveitis, and glaucoma can help you sort out what you are seeing.

How FIP and FIV Cause Uveitis

FIP and the eye

FIP is a severe disease caused by a feline coronavirus [4]. Most cats exposed to this virus do not develop FIP. The severe form is thought to involve a mutation in the virus plus an unusual immune response in that individual cat [4].

The virus sets off inflammation in blood vessel walls, and the eye is rich in small vessels. That is why the uvea, the retina, and the choroid are common targets. FIP is seen most often in cats 6 months to 2 years old, and purebred cats (Persian, Abyssinian, Bengal, Birman, Himalayan, Ragdoll, and Rex) are more likely to be affected [4].

Eye involvement is common. Among 118 cats diagnosed with FIP, 40.1% had eye abnormalities at their first exam [2]. In a separate review of 61 cats with FIP, 33% had eye disease, and all of those changes were tied to uveitis. Of the 20 cats with eye involvement, 20% had anterior uveitis, 25% had posterior uveitis, and 55% had panuveitis (inflammation throughout the eye) [5]. Eye disease appeared in both the effusive (wet) and non-effusive (dry) forms of FIP [5].

For a full picture of the disease itself, see FIP in Cats: Symptoms, Diagnosis, and How It Is Treated Today.

FIV and the eye

FIV attacks the immune system and leaves a cat vulnerable to other infections [6]. Over time, the immune deficiency allows ordinary bacteria, viruses, protozoa, and fungi from the everyday environment to cause serious illness [6].

FIV is on the list of common infectious diseases that can cause anterior uveitis in cats [1]. The mechanism is usually indirect. A weakened immune system lets other organisms take hold, and the eye becomes inflamed as part of that process. Because FIV is not curable, the goal is to control the eye inflammation and manage any secondary infection [6].

The main way FIV spreads is through bite wounds from an infected cat [6]. Casual contact like sharing water bowls or grooming does not appear to spread it efficiently, so cats in stable households that do not fight are at low risk [6]. Mothers can rarely pass it to kittens, and the risk rises if the mother is infected during pregnancy [6].

Risk Factors and Other Causes to Rule Out

FIP is most common in young cats and in certain purebreds [4]. FIV is most common in cats with outdoor access and a history of fighting [6].

Uveitis has many other possible causes, and your vet will consider them. The list includes feline leukemia virus, toxoplasmosis, generalized fungal infection, and leptospirosis [1]. In one small study of 37 cats with uveitis, 2 had antibodies to Leptospira, but none had Leptospira DNA in their eye fluid, so the role of this bacteria in feline uveitis is still not well established [7].

Systemic inflammation itself can drive eye disease. In a study of hospitalized dogs and cats, 38% of patients with systemic inflammatory response syndrome developed anterior uveitis, compared with 7.7% of patients hospitalized without it [8]. That is a reminder that the eye is often a window into the rest of the body.

How Veterinarians Diagnose It

Diagnosis happens in two layers: confirming the eye inflammation, then finding the cause.

The eye exam

Your vet will examine both eyes with a light and a magnifying lens, check the pupils, and measure pressure inside the eye. They may use a slit lamp or a stain to look at the cornea. An ophthalmologist may use advanced imaging. In one reported case, a 4-month-old cat with severe uveitis and persistent corneal swelling needed anterior segment optical coherence tomography to find a detachment of Descemet's membrane, a layer inside the cornea [9].

Testing for FIP and FIV

For FIV, a blood test detects antibodies to the virus. For FIP, diagnosis is more involved. Your vet may combine history, physical exam, blood work, imaging, and fluid analysis. In the case above, testing the fluid inside the eye found coronavirus RNA, though the biotype test did not confirm the mutation linked to FIP virus [9]. That shows how tricky FIP diagnosis can be, and why vets use several pieces of evidence together.

Ruling out look-alikes

Not every young cat with uveitis has FIP. A study comparing 22 kittens with a mild, self-resolving uveitis to 8 kittens with confirmed FIP-associated uveitis found real differences [3]. The self-resolving cases were mostly domestic kittens from shelters and had eye signs for only 1 to 2 weeks before the exam. The FIP cases were more often purebred or stray cats and had eye signs for more than 2 months [3]. The FIP group also had more severe findings on exam [3]. Your vet uses these patterns, plus testing, to narrow things down.

Feature	FIP-associated uveitis	FIV-associated uveitis
Typical trigger	Coronavirus mutation plus immune response [4]	Immune deficiency allowing other infections [6]
Common eye findings	Anterior uveitis, keratic precipitates, chorioretinitis [2]	Anterior uveitis [1]
How it spreads	Contact with infected cats, often in colonies [4]	Mainly bite wounds [6]
Main treatment	Antiviral drugs plus anti-inflammatory eye care [2][5]	Supportive care, control of secondary infection [6]
Outlook	Often improves with antiviral treatment [2]	Many cats live normal lifespans if not also FeLV positive [6]

Treatment Options

Treatment has two goals: calm the eye and treat the underlying virus.

Eye-directed care

Your veterinarian will choose anti-inflammatory eye drops or oral medication based on the exam. They calculate the dose from your cat's weight and health, so never use leftover drops from another pet or an old prescription. A cat with uveitis may also need pain relief. Some cats need medication to keep the pupil from sticking to the lens.

Antiviral treatment for FIP

This is the biggest change in feline medicine in years. In a study of 118 cats with FIP treated with the antiviral GS-441524, eye findings improved significantly across all parts of the eye, with rapid improvement in the first 7 days [2]. A separate review of 61 cats found that eye disease occurred in both wet and dry FIP, and cats responded to remdesivir, GS-441524, or a combination of the two [5].

In the case of the 4-month-old cat with severe uveitis, inflammation improved after GS-441524 was started along with anti-inflammatory and supportive eye treatment [9]. The corneal swelling in that cat persisted because of the membrane detachment, which shows that some eye damage takes longer to resolve or may leave lasting changes [9].

Antiviral treatment for FIP is prescribed and monitored by your veterinarian. The drug, the dose, and the length of treatment are set for your individual cat.

Managing FIV

There is no cure for FIV [6]. Care focuses on keeping the cat indoors, treating secondary infections promptly, and controlling inflammation. The good news is that cats with FIV often live average lifespans as long as they are not also infected with feline leukemia virus [6].

Recovery, Outlook, and Long-Term Management

The outlook depends on the cause, how quickly treatment starts, and how much damage the eye has already taken.

For FIP, the eye often responds early. Improvement within the first week of antiviral therapy is common [2]. Even so, some changes can linger. Persistent corneal edema in one reported cat was traced to a structural problem inside the cornea that did not resolve with antiviral treatment alone [9].

For FIV, the eye inflammation may come and go with the cat's overall health. Regular checkups help catch flare-ups early.

Long-term care usually includes:

Recheck eye exams, even when the eye looks normal
Monitoring for cloudiness, redness, or squinting at home
Blood work to track the underlying disease
Keeping your cat indoors to lower exposure to other infections
Watching for vision changes, since uveitis can affect sight [1]

If your cat seems to be losing vision, this guide on sudden blindness, retinal detachment, and uveitis explains what can cause it.

Prevention

You cannot fully prevent uveitis, but you can lower the odds and catch problems early.

Test new cats for FIV before bringing them home, and keep FIV-positive cats indoors and separated from cats who fight [6].
Reduce fighting. FIV spreads mainly through bite wounds [6].
Keep young cats, especially purebreds, on a regular vet schedule, since FIP is most common between 6 months and 2 years [4].
Know the early eye signs. Squinting, redness, and a protruding third eyelid are reasons to call your vet [1].
Treat other illnesses promptly. Systemic inflammation raises the risk of eye involvement [8].

For everyday eye care and what normal cat eyes look like, see Cat Eyes: Understanding Feline Vision, Common Eye Problems & Care Tips.

Limitations and When to Contact a Veterinarian

No article can diagnose your cat. Eye inflammation has many causes, and the treatment for each one is different. Your veterinarian needs to examine your cat and run the right tests.

Call your veterinarian the same day if you notice:

Squinting, tearing, or keeping one eye closed
Redness in the white of the eye
A cloudy or blue-gray cornea
A pupil that looks different from the other eye
Your cat rubbing its face or avoiding bright light

Go to an emergency clinic now if:

Your cat suddenly cannot see, bumps into furniture, or seems disoriented
The eye looks swollen, bulging, or has a visible wound
Your cat is crying out, vomiting, or seems very painful
Both eyes changed within hours

Schedule a routine visit if your cat has a known FIP or FIV diagnosis and you want a baseline eye exam, or if a previous bout of uveitis seems to be returning. Early treatment protects vision.

Frequently Asked Questions

Can uveitis be the first sign of FIP in a cat?

Yes. Uveitis is often the only sign of a whole-body infection, which is why an eye exam matters so much [1]. In one group of cats with FIP, 40.1% already had eye abnormalities when they were first diagnosed [2]. If your young cat has a red or cloudy eye and seems otherwise fine, that eye change may be the first clue.

Does FIV always cause eye problems?

No. FIV weakens the immune system over time, and uveitis is one possible result, not a guaranteed one [1][6]. Many cats with FIV stay comfortable for years. Regular checkups help your vet catch eye inflammation before it causes lasting damage.

Is uveitis in cats painful?

Yes. Uveitis is an inflammatory condition, and cats with it often squint, avoid light, and paw at their face. Pain relief is part of treatment. Tell your vet if your cat seems uncomfortable, because the plan can be adjusted.

Can antiviral treatment reverse eye damage from FIP?

It often improves eye inflammation, sometimes within the first week of treatment [2]. Some damage, such as a structural problem inside the cornea, may persist even when the inflammation settles [9]. Your vet will recheck the eyes during and after treatment to see how much has recovered.

Can my other cats catch uveitis from my cat?

Uveitis itself is not contagious. The infections behind it can spread, though. FIV spreads mainly through bite wounds, and casual contact like shared bowls does not appear to spread it efficiently [6]. FIP is linked to coronavirus exposure, which is more common in crowded or colony settings [4]. Ask your vet about testing and separating cats if fighting is an issue.

References

Disorders of the Anterior Uvea in Cats - Cat Owners. Merck Veterinary Manual.
Ocular findings in cats with feline infectious peritonitis treated with GS-441524: a preliminary prospective study of 118 cases. Journal of feline medicine and surgery, 2026.
Clinical and clinicopathologic features of an undifferentiated resolving uveitis in kittens similar to that seen with feline infectious peritonitis. Journal of the American Veterinary Medical Association, 2026.
Feline Infectious Peritonitis (FIP) - Cat Owners. Merck Veterinary Manual.
Treatment With Remdesivir Alone or in Combination With GS-441524 in Cats With Ocular Involvement of Feline Infectious Peritonitis: An Observational Case Series. Journal of veterinary internal medicine, 2025.
Feline Immunodeficiency Virus (FIV). Cornell University College of Veterinary Medicine.
Evaluation of Leptospira species as a cause of endogenous uveitis in cats: a pilot study. Journal of feline medicine and surgery, 2026.
Prevalence of anterior uveitis in cases of systemic inflammatory response syndrome in dogs and cats. Veterinary ophthalmology, 2025.
Anterior Segment OCT Diagnosis of Descemet's Membrane Detachment in a Cat With Suspected FIP-Associated Uveitis. Veterinary ophthalmology, 2026.