Cat uveitis is inflammation of the uveal tract — the eye's pigmented vascular layer — that causes cloudiness, squinting, and a visibly changed iris color. It is a serious condition because untreated inflammation rapidly damages the lens, retina, and drainage angle, leading to glaucoma or blindness. Uveitis in cats almost always signals an underlying systemic disease requiring investigation.
Last reviewed: June 2026
What Is Cat Uveitis?
Uveitis is inflammation of the uvea, which comprises the iris, ciliary body, and choroid. In cats, uveitis is nearly always a sign of systemic illness rather than a primary eye disease. The most common infectious causes include feline leukemia virus (FeLV), feline immunodeficiency virus (FIV), feline infectious peritonitis (FIP), toxoplasmosis, and bartonellosis. Lens-induced uveitis (from a hypermature cataract) and lymphoma infiltrating the uveal tract are important non-infectious causes.
As described in Côté's Clinical Veterinary Advisor, bilateral uveitis in a cat strongly suggests an infectious or neoplastic systemic cause, while strictly unilateral uveitis may indicate trauma, a foreign body, or less commonly an isolated fungal infection (Cryptococcus or Histoplasma in endemic regions). Per the AAFP Feline Retrovirus Guidelines, 2020, FeLV and FIV testing should be performed in every cat presenting with uveitis of unknown cause.
Signs of Uveitis in Cats
- Blepharospasm — squinting, holding the eye partially or fully closed
- Epiphora — tearing or eye discharge
- Corneal cloudiness (edema) — hazy or blue-white appearance of the cornea
- Aqueous flare — a hazy, cloudy appearance in the anterior chamber ("headlight-in-fog")
- Iris color change — dullness, darkening, or irregular color vs. the unaffected eye
- Miosis — constricted pupil in the affected eye (from ciliary body spasm)
- Hypopyon — white or grey sediment visible at the bottom of the anterior chamber (serious)
- Hyphema — blood in the anterior chamber (associated with hypertension or coagulopathy)
In cats, chronic low-grade uveitis may be surprisingly subtle — owners may only notice an iris color change or slight squinting that comes and goes. Any color asymmetry between the two irises warrants prompt veterinary evaluation.
Diagnosis
Your vet will perform a complete ophthalmic exam including slit-lamp biomicroscopy (anterior chamber evaluation), tonometry (intraocular pressure), and fundic exam. Uveitis typically causes LOW intraocular pressure initially (due to decreased aqueous production); secondary glaucoma causes HIGH pressure. Systemic workup includes CBC/chemistry, retrovirus testing, toxoplasmosis serology, blood pressure measurement, thoracic radiographs, and abdominal ultrasound. In older cats, lymphoma cytology or FIP testing (serum protein electrophoresis, effusion analysis) may be indicated.
Treatment
Treatment targets both the underlying cause and the intraocular inflammation:
- Topical corticosteroids (prednisolone acetate 1% q4–8h) reduce anterior chamber inflammation; contraindicated if corneal ulceration is present — fluorescein stain must confirm corneal integrity before steroid use
- Topical NSAIDs (diclofenac, flurbiprofen) as an alternative or adjunct when steroids are contraindicated
- Topical atropine 1% dilates the pupil (prevents posterior synechia — adhesions of the iris to the lens) and reduces ciliary body spasm
- Systemic treatment addresses the underlying cause: antiviral therapy for FIP (GS-441524), anti-toxoplasma clindamycin, anti-bartonella doxycycline, or chemotherapy for lymphoma
Per the AAFP-AAHA Feline Life Stage Guidelines, 2021, regular monitoring every 3–6 months is recommended for cats with confirmed retroviral infection, as uveitis and intraocular lymphoma can develop years after initial diagnosis.
When to See a Vet
Call your vet today if:
- Your cat has a cloudy, hazy, or blue-tinted eye
- One eye looks different from the other — color change, pupil size, discharge
- Your cat is squinting persistently or rubbing one eye
- You see what looks like blood or white material inside the eye
Go to the ER immediately if:
- Your cat's eye is bulging or appears much larger than the other (possible acute glaucoma)
- Your cat seems suddenly blind — walking into objects, dilated pupils that don't respond to light
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Frequently Asked Questions
Can uveitis cause blindness in cats? Yes. Untreated or poorly controlled uveitis causes progressive damage: posterior synechia (iris-lens adhesion), cataract formation, retinal detachment, and secondary glaucoma. Each complication compounds the risk of permanent vision loss. Early treatment significantly improves the chance of preserving sight.
How much does treating cat uveitis cost? An ophthalmology or general vet exam with tonometry runs $100–250. Systemic workup (bloodwork, retrovirus testing, radiographs) adds $300–600. Specialist ophthalmology consultation costs $200–400. Ongoing treatment including topical medications and recheck exams may run $100–300/month during active management.
Is uveitis in cats painful? Yes — acute uveitis is uncomfortable to painful due to photophobia (light sensitivity) and ciliary spasm. Many cats become reclusive or stop engaging in normal activities. Pain management with cycloplegic agents (atropine) is an important part of treatment.
What does FIP uveitis look like? FIP-associated uveitis often presents bilaterally with aqueous flare, hypopyon (white cellular sediment), and iris discoloration. It may occur with or without the classic wet-form abdominal effusion. The wet-to-dry form transition can manifest as ocular signs. Diagnosis requires specialized testing including albumin:globulin ratio, effusion analysis, or RT-PCR.
Still Not Sure if Your Cat Needs a Vet?
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