A 7-year-old spayed female Persian cat is examined for ch...

Alright, a 7-year-old Persian with a non-healing corneal ulcer and chronic blepharospasm and epiphora. This immediately signals a need for a very thorough and systematic approach, as "non-healing" in a cat is a red flag for specific underlying issues that are often missed with a superficial examination.

First, I commend you for performing the fluorescein stain and Schirmer Tear Test (STT). The positive fluorescein confirms an epithelial defect, and a normal STT, while less commonly low in cats, is still a critical piece of information, ruling out KCS as a primary contributing factor. However, the chronic nature and the breed (Persian cats are notorious for specific ocular problems) direct my suspicion.

My immediate priority would be to perform a complete ophthalmic examination, following my established sequence:

Distance Examination: I'd pay close attention to the severity of the blepharospasm, the character of the epiphora (serous, mucoid, mucopurulent?), and any obvious eyelid conformational abnormalities common in Persians, such as medial canthal entropion or nasal fold trichiasis.

Neuro-Ophthalmic Assessment: PLRs and menace responses would be assessed, primarily to rule out concurrent neurological issues, though less likely to be the primary cause of a non-healing ulcer.

Intraocular Pressure (IOP): This is non-negotiable. Even with a corneal ulcer, measuring IOP is crucial. Hypotony (<10 mmHg) would suggest uveitis, which can cause secondary corneal disease. Elevated IOP (>25 mmHg) would suggest glaucoma, which can also be painful and affect corneal health.

Slit Lamp Biomicroscopy (or detailed focal light source exam): This is where the bulk of my diagnostic effort would be. I need to characterize that ulcer meticulously:

* Eyelids: Confirm or rule out medial canthal entropion, distichiasis, or ectopic cilia that could be chronically irritating the cornea. Persian cats often have issues with nasal folds rubbing the cornea.
* Cornea:
* Depth: Is it truly superficial, or is there stromal involvement? Is there any evidence of a descemetocele (fluorescein pooling around the base, but not staining the base itself)?
Morphology: This is critical* in a cat. Is there a dendritic (branching) pattern to the ulcer? This is pathognomonic for Feline Herpesvirus-1 (FHV-1) keratitis. Is it a larger, geographic ulcer? FHV-1 can also present this way.
Corneal Sequestrum: This is a major* differential in a Persian cat with chronic keratitis. Look for a brown-to-black corneal plaque. This can be superficial or deep and is often associated with FHV-1 or chronic irritation.
* Eosinophilic Keratitis ("Proliferative Keratitis"): Look for pinkish, raised, granular lesions, often starting at the limbus and extending onto the cornea. This can also be associated with FHV-1.
* Foreign Body: Thoroughly check the conjunctival fornices and under the third eyelid.
* Vascularization/Edema/Infiltrate: Note the pattern and depth.

Fluorescein Stain & Seidel Test (if perforation suspected): Already done, but I would re-evaluate the pattern myself.

Fundic Examination: After pupil dilation (if safe, i.e., no anterior lens luxation or acute glaucoma), to rule out any posterior segment disease, though less likely to be the primary cause of this specific presentation.

Based on your history and the breed, my top differentials for this non-healing feline corneal ulcer are:

Feline Herpesvirus-1 (FHV-1) Keratitis: Chronic, non-healing ulcers, especially geographic or dendritic, are highly suggestive. Stress and systemic illness can reactivate the virus.

Corneal Sequestrum: Very common in Persians due to their brachycephalic conformation and often secondary to chronic FHV-1 or other irritants (like eyelid abnormalities).

Eyelid Abnormalities: Medial canthal entropion or nasal fold trichiasis causing chronic irritation and preventing healing.

Persistent Foreign Body: Less common for chronic non-healing, but always a possibility.

Crucially, cats DO NOT get canine Spontaneous Chronic Corneal Epithelial Defects (SCCEDs/indolent ulcers). Therefore, epithelial debridement with a diamond burr or grid keratotomy is not appropriate and can worsen the condition in a cat.

My immediate recommendations would be:

Corneal Cytology: Gently scrape the ulcer bed with a cytobrush or sterile spatula and submit for cytology. This can reveal herpesviral inclusions, eosinophils, or secondary bacterial/fungal organisms.

FHV-1 PCR: A definitive diagnostic test for herpesvirus, either from the cornea or conjunctiva.

Topical Broad-Spectrum Antibiotic: To prevent or treat secondary bacterial infection. I would start with ofloxacin 0.3% drops q8-12h or NeoPolyBac ophthalmic ointment q8-12h. If there's any suspicion of a deep or melting ulcer, frequency would be increased (q2-4h).

Topical Atropine 1%: If IOP is normal or low, atropine 1% drops or ointment BID-TID can be used to relieve pain from ciliary spasm. Be aware that cats can salivate from the bitter taste if it drains into the oral cavity via the nasolacrimal duct.

E-collar: Absolutely essential to prevent self-trauma.

Consider Systemic Antiviral (Presumptive FHV-1): Given the chronicity and breed, I would strongly consider starting famciclovir 90 mg/kg PO every 12 hours while waiting for definitive FHV-1 PCR results. A topical antiviral like cidofovir 0.5% drops (compounded) BID could also be added.

Surgical Consultation: If a corneal sequestrum is identified, surgical keratectomy is usually required for resolution, especially if deep or painful. Eyelid abnormalities like entropion or nasal fold trichiasis would also require surgical correction.

A critical warning: NEVER use topical corticosteroids (e.g., prednisolone acetate or dexamethasone) on an eye with a positive fluorescein stain. Steroids will inhibit healing, exacerbate herpesvirus replication, and can rapidly lead to a melting ulcer or perforation.

This cat's condition is not a simple ulcer and requires a specialist's approach to identify and address the underlying cause. I would strongly recommend referral for complete ophthalmic evaluation and management.