What causes third eyelid prolapse?

Third eyelid prolapse can be caused by eye infection, local inflammation, orbital mass, or trauma, and may also be associated with systemic disease. The exact cause requires veterinary examination and, where necessary, imaging or laboratory tests — consult your vet for an accurate diagnosis.

Does third eyelid prolapse require surgery?

Whether surgery is needed depends on the underlying cause and severity. Some cases can be managed with medication or conservative treatment, while complex cases or those causing functional impairment may require surgical intervention — follow your vet's assessment.

Can I clean my pet's eye discharge at home?

Mild clear discharge can be gently wiped away with a clean gauze dampened with cooled boiled water. However, if the discharge is yellow-green or purulent, has an odour, or your pet shows signs of pain or bleeding, seek veterinary care promptly and follow your vet's instructions.

Can third eyelid prolapse affect my pet's vision?

If the third eyelid covers the cornea, or is accompanied by corneal damage or severe inflammation, vision may be temporarily affected. A vet should examine the cornea and intraocular structures and arrange appropriate treatment and follow-up.

How much do the tests and treatment usually cost?

Costs vary by clinic and region — ask your vet for an estimate before proceeding.

Disease Guide

Third Eyelid Prolapse in Dogs & Cats: Symptoms, Diagnosis & Treatment [2025]

Abnormal protrusion of the third eyelid, reflecting neurological or ocular conditions

Take 1 minute to check the symptoms first

Last updated: 2026/01/06

Pethealthmap Editorial Team

Sources: ACVO, WSAVA, National Taiwan University Veterinary Hospital

When to See a Vet

Seek Emergency Care Immediately

•Heavy eye bleeding that does not stop
•Sudden loss of vision with frequent collisions into objects
•Rapidly worsening eye swelling with continuous crying in pain

Schedule a Clinic Visit Soon (within 24–72 hours)

•Third eyelid remains protruded for an extended period with no improvement
•Eye discharge is yellow-green in color or has a foul odor
•Persistent frequent blinking or pawing at the eye

01What symptoms indicate something is wrong?

When the third eyelid protrudes, pets commonly show eye redness, increased discharge, and signs of ocular discomfort; vision or light response may also be affected. Below are the common observable changes and emergency warning signs.

Persistent eye redness, inflammation, or conjunctival hyperaemia
Visible partial or complete protrusion of the third eyelid covering the cornea
Frequent blinking, pawing at the eye, or avoidance of light
Increased ocular discharge, which may be clear, yellow-green, or malodorous
Changes in activity or eating and drinking habits; may become withdrawn or reluctant to be touched

Seek emergency care immediately if you notice the following symptoms:

⚠️ Corneal perforation or obvious change in eyeball shape
⚠️ Sudden significant loss of vision or complete unresponsiveness to light
⚠️ Heavy ocular bleeding or rapidly worsening swelling

02How to assess the situation at home: Key observations and criteria for seeking emergency care

Observing and recording key information at home before your appointment helps your vet assess the condition and prioritise care more efficiently.

Record the exact time symptoms first appeared and when they worsened
Take close-up photos and short videos (showing blinking and eye closure) with your phone for reference
Note any changes in alertness, appetite, or activity level
Monitor the colour, amount, odour, and persistence of any discharge
Record any noticeable changes in weight or water intake as well

03How will the vet diagnose this condition? Common examination procedures

The veterinary clinic will carry out a comprehensive ophthalmology assessment, supplemented by imaging or laboratory tests where necessary, to identify the underlying cause and evaluate severity.

Complete ophthalmic physical examination

including pupillary light reflex and menace response testing

Fluorescein staining

to check for corneal abrasions or ulcers

Intraocular pressure measurement

to assess for elevated or abnormal IOP

Ocular ultrasound

to evaluate deep ocular or intraocular structures for abnormalities

X-ray or CT scan

to examine the orbit and surrounding tissue; MRI or biopsy may be indicated in complex cases

04How is this condition treated and managed? Medication, dietary adjustments, and home care guide

Treatment is determined by the underlying cause; follow-up after medication or surgery is equally important, as regular rechecks reduce the risk of recurrence and complications.

Treatment — medical or surgical — is chosen based on the underlying cause, with follow-up appointments scheduled accordingly
Apply topical medications (eye drops or ointments) strictly as directed by your vet
Return for scheduled rechecks after surgery or once symptoms improve, to assess recovery
Prevent your pet from scratching their eye at home; use an Elizabethan collar if necessary
Complex or recurrent cases should be referred to a specialist veterinary hospital with dedicated ophthalmology equipment

05What to prepare before your vet visit: Key information to help your vet assess quickly

Prepare photos and short videos taken before and after symptom onset (including views with the eye closed and from the side)

Record the onset time, fluctuation of symptoms, and any home care measures you have taken

Describe the colour, volume, and any odour of the discharge

Note whether vision appears affected and how your pet responds to touch around the eye

Bring past ophthalmology reports and a list of current medications or supplements

Book an appointment at a clinic equipped for ocular imaging and specialist ophthalmology assessment

This content is for reference only and cannot replace a professional veterinary diagnosis. If your pet shows signs of illness, please seek veterinary care promptly.

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