Ectropion in dogs – outward-turning eyelids

Overview

Normally, the eyelid edge rests against the eye's surface and protects it. In ectropion, the edge is loose and turns outwards, often because the lid is too long.

The conjunctiva is thin tissue covering the inside of the lids and part of the eyeball. The cornea is the transparent structure at the front of the eye, which must remain healthy for vision.

Macroblepharon means an excessively large eyelid opening, which may accompany ectropion. Ectropion differs from entropion, in which the eyelid edge turns in towards the eye.

However, different parts of the same eye can have inward and outward turning at once. This diamond-shaped eyelid conformation is called 'diamond eye'.

A British study published in 2025 estimated the annual proportion of dogs diagnosed with ectropion in 2019 at 0.04%. This reflects diagnoses recorded in practices, and mild unrecognised cases may have been missed.

Causes

Head and eyelid conformation

A combination of a large head, abundant skin and a relatively small eyeball can prevent the lid from resting against the eye. Overlong lids and weak support at the outer eye corner can maintain the abnormal position.

Heavy ears and facial skin folds can also affect eyelid position. Several genes are thought to contribute to inherited conformational ectropion.

In a long-muzzled dog, the inner eye corner may be so open that discharge collects there. As skin elasticity changes with age, drooping lids may sag further.

The circular muscle that closes the lids surrounds the eyelid opening and helps protect the eye through blinking. Supporting eyelid structures attach to the inner and outer walls of the eye socket, helping the lids close in the correct position.

Causes that develop later

Scarring after an eyelid injury can pull the edge outwards. Facial nerve paralysis can cause ectropion on one side even in a dog without a breed predisposition.

Acquired ectropion may also be associated with hypothyroidism. Longstanding inflammation around the eye can change eyelid position.

Overcorrection during entropion surgery can turn the lid in the opposite direction, outwards. A condition affecting nerves and muscles may also underlie acquired ectropion.

Risk factors

Conformational ectropion is most common in large breeds with long lids and loose skin. Recognised predisposed breeds include Bloodhounds, Bullmastiffs, Great Danes, Newfoundlands and St Bernards.

It also occurs in many spaniels, including Clumber Spaniels and Cocker Spaniels. In the British study, the annual proportion of Neapolitan Mastiffs diagnosed with ectropion was 4.30%.

The corresponding proportion in St Bernards was 1.72%. In Basset Hounds, it was 1.59%.

In Great Danes, the proportion diagnosed was 1.47%. Acquired ectropion can develop in any breed and at any age.

A small dog can also have an excessively large eyelid opening, although conformational ectropion mainly affects large breeds.

Typical symptoms

A common finding is a lower lid drooping away from the eye, exposing more conjunctiva than usual. The British study's symptom comparison involved 167 dogs with at least one recorded eye sign.

• The eye is red or the exposed conjunctiva looks inflamed. Redness was recorded in 46 dogs, or 27.54% of those in the symptom comparison.

• Thick, mucoid discharge collects at the eyelid edge. Discharge was recorded in 87 dogs, or 52.10%.

• Tears run onto the face from the inner eye corner. Excessive tearing was recorded in 25 dogs, or 14.97%.

• Fur beneath the eye becomes stained brownish.

• Your dog rubs the eye with a paw or the face against a surface.

• Squinting or keeping the eye closed may indicate a painful corneal injury.

Ectropion often affects both eyes, but the acquired form may affect only one. In the British study, information on which side was affected was available for 230 cases; 179, or 77.83%, were bilateral.

Mild ectropion may cause few symptoms despite the abnormal lid position.

Complications and consequences

Damage to the eye's surface

Exposed conjunctiva encounters wind, dust and UV radiation. Irritation and secondary bacterial infection can maintain repeated or persistent conjunctivitis.

Poor distribution of the tear film can leave the corneal surface dry and inflamed. In a superficial corneal ulcer, the protective surface cell layer is damaged.

A deep ulcer may extend into the cornea's supporting tissue, the stroma. At worst, a deep ulcer can cause the eye to perforate.

An excessively large opening may prevent the lids from closing completely. If the opening is large and the socket shallow, an impact or fight may predispose the eyeball to prolapse from the socket.

Hairs on an inward-turning lid section may rub the highly sensitive eye surface and increase pain.

Outlook

Properly treated ectropion generally has a good outlook with topical care or after surgery. However, corneal scarring treated late may leave permanent visual impairment despite eyelid correction.

Diagnosis at the vet

Eyelid function and the eye's surface

The vet usually identifies ectropion during clinical examination of the eyes and lids. Possible entropion is assessed too, because the abnormalities may coexist.

Corneal staining reveals whether an ulcer has developed. Fluorescein dye adheres where the protective corneal surface cells are missing.

The stained area appears green under a blue examination light. In official eye screening, a stretched eyelid opening longer than 40 millimetres is recorded as macroblepharon.

An opening longer than 45 millimetres falls into the severe category. A severe classification also applies when exposure or persistent irritation has caused corneal changes.

Examination of the lids and front of the eye is recommended before pupil dilation. Official eye screening assesses structures including the cornea, lens and back of the eye as well as the lids.

If the finding's significance remains uncertain, some reports may use an 'undetermined' category rather than a definite disease classification.

Investigating changes that appear in adulthood

Ectropion is often diagnosed before one year of age, but the acquired form may appear later. However, the British patient study found a median age of 2.15 years at the first recorded diagnosis among the 303 dogs with known age information.

Blood and urine tests may investigate an acquired cause in an older dog. Thyroid function is checked when appropriate if signs are consistent with hypothyroidism.

Suspected neuromuscular disease may require a muscle or nerve biopsy. Antibodies targeting muscle fibres may be tested when investigating certain muscle diseases.

Treatment

Topical care for mild ectropion

The vet chooses treatment according to eyelid position and damage to the eye's surface. Lubricating eye drops or ointments protect the drying cornea and conjunctiva.

Rinsing with an eye wash selected by the vet may be enough as part of treatment for a mild case. Topical anti-inflammatory medication can temporarily settle mild or intermittent inflammation.

For a corneal ulcer, the vet may prescribe topical antibacterial medication. Separate vet-prescribed medication may be needed for pain relief.

A protective collar can prevent rubbing and further injury while an ulcer heals. An uncomplicated corneal ulcer often heals within 3–5 days, but ongoing structural irritation can prevent healing.

If conjunctivitis recurs, lubrication and other topical care may be needed throughout the dog's life.

Corrective eyelid surgery

Surgery aims to restore the lid's shape so that it protects the eye better. An overlong lid can be shortened surgically to bring its edge closer to the eye.

A severe or complex case may be referred to a vet with expertise in eye disease. When there is substantial swelling or inflammation, correction may be planned in stages.

Two separate operations are sometimes needed to avoid overcorrection. Overcorrection can turn the lid inwards and create a new entropion problem.

What has been recorded in treatment plans?

In the British study, a treatment plan was available for 201 ectropion cases. Of these plans, 60.20% included medical treatment.

Surgery was included in 32.34% of recorded plans. An operation actually performed was recorded for 12 dogs, or 3.93% of the year's 305 new cases.

A planned procedure and its recorded completion are different things; these figures cannot determine whether an individual dog needs surgery.

Prevention

In breeding, functional eyelids that rest against the eye reduce problems associated with conformational ectropion. Some breed-club guidance requires a breeding dog with mild ectropion or macroblepharon to have a mate unaffected by the same condition.

A dog with severe symptoms or needing corrective surgery should not be used for breeding. A breed-typical appearance does not make an eyelid conformation healthy if it causes pain or inflammation.

Some official screening schemes continue to record surgically corrected ectropion as an affected result, based on the original diagnosis.

Breeding choices aim particularly to reduce inherited eye problems that cause pain or require ongoing medication or surgery.

Important for dog owners

Record whether redness, discharge or rubbing recurs during topical treatment, because conjunctivitis may return.

Bring previous eye examination results and details of eyelid operations to the appointment. Mention if the change appeared only in adulthood or clearly affects just one eye.

A temporary improvement in inflammation does not necessarily correct the eyelid's abnormal position.

A corneal ulcer that does not heal as expected or extends deeply needs closer assessment by a veterinary eye specialist.

Agree a follow-up appointment as part of the treatment plan and keep the written instructions. New pain, closure of the eye or cloudiness requires urgent assessment even when ectropion has been present for a long time.

Frequently asked questions

Is ectropion the same as entropion?

In ectropion, the eyelid edge turns outwards; in entropion, it turns towards the eye. A dog may have both changes in different parts of the lid, so a drooping lower lid alone does not describe the whole eye's conformation.

Can ectropion be treated without surgery?

Mild ectropion can be managed with lubricating drops or ointments selected by the vet to protect the surface from drying. In severe cases, however, surgical shortening may be needed to make the lid protect the eye better.

Why does the eye water if it is also dry?

An abnormal position of the inner part of the lid can make tears run onto the face from the inner corner. At the same time, tears may not spread evenly over the surface, allowing the cornea to dry or become inflamed despite excessive watering.

Can an adult dog develop ectropion?

Acquired ectropion can develop at any age and need not relate to the breed's usual eyelid conformation. Possible causes include scarring or facial nerve paralysis, so a later-onset change is also investigated for an underlying condition.

Can a dog with surgically corrected ectropion have puppies?

Severe ectropion requiring corrective surgery is a reason not to breed from the dog, even if treatment improves eye function. Some breed-club guidance requires an unaffected mate for a mild finding, so the original diagnosis should remain in breeding records.