CONDITION

Blepharitis in Dogs

Blepharitis is inflammation of the eyelids. It can affect one or both eyes, and may involve the skin, the eyelid margins, or the glands and follicles within the lid itself. The inflammation can arise from infection, allergy, immune activity, anatomical factors, or conditions affecting the skin more broadly. Owners often notice redness, swelling, discharge, crusting along the lash line, or signs that the eye area is uncomfortable: rubbing, mild squinting, or increased tearing. The eyelids may appear thickened or the hair around them may be lost. In some cases blepharitis occurs alongside other skin or eye conditions, and in others it appears on its own. This page explores the signals that may accompany eyelid inflammation, the mechanisms and causes that can drive it, how it is investigated, and the range of approaches used to manage it.

Why this matters now

Blepharitis can appear at any age, though certain patterns tend to cluster at different life stages. Young dogs may develop eyelid inflammation linked to congenital eyelid abnormalities, demodicosis, or juvenile-onset allergic skin disease. In puppies, usually between about 3 weeks and 4 months of age, sudden swelling of the eyelids, lips and muzzle with swollen lymph nodes under the jaw can be juvenile cellulitis ('puppy strangles'). This is thought to be an immune-mediated condition. Affected puppies are often lethargic, feverish or off their food, and the skin can scar permanently, particularly when treatment is delayed. Middle-aged and older dogs more often show blepharitis associated with immune-mediated conditions, chronic allergies, or age-related changes in the meibomian glands, which sit within the eyelids and open along the margins. Brachycephalic breeds and those with prominent eyes or loose facial skin may be predisposed due to anatomical factors that affect eyelid positioning and tear distribution.

The course of blepharitis varies widely depending on the underlying cause. In some dogs, eyelid inflammation appears suddenly and resolves within days to weeks once a trigger, such as a bacterial infection or contact irritant, is addressed. In others, the condition follows a relapsing pattern, with periods of flare and partial resolution, particularly when driven by allergy or immune activity. Chronic blepharitis may lead to progressive changes in the eyelid structure, including thickening, scarring, or persistent gland dysfunction, which can sustain low-grade inflammation even between obvious flares. Sudden swelling of the eyelids and face, for example after an insect sting, is usually an acute allergic reaction (angioedema) rather than the longer-running eyelid inflammation described on this page. When the swelling comes with vomiting, diarrhoea, drooling, weakness, collapse or difficulty breathing, it can be part of anaphylaxis, a whole-body allergic reaction that can progress over minutes to hours and can be fatal.

Signals & patterns

Early signals

Redness along the eyelid margin

The edge of the eyelid, where the lashes emerge, may appear pinker or redder than usual. This reflects increased blood flow to the inflamed tissue and is often one of the first visible changes.

Pawing or rubbing at the eye

A dog may use a paw or rub the face against furniture or the floor. This behaviour often signals discomfort or itching around the eyelid, which can accompany even mild inflammation.

Mild discharge or tearing

The eye may appear wetter than usual, or a small amount of clear to mucoid discharge may collect at the inner corner. This can result from irritation of the eyelid margin or disruption of the normal tear film.

Crusting at the lash line

Dried secretions or flakes may appear along the base of the lashes, sometimes forming small crusts. This can reflect inflammatory exudate, disrupted gland secretions, or secondary bacterial colonisation.

Squinting or partial eye closure

The affected eye may be held slightly more closed than the other, or the dog may blink more frequently. Mild squinting can accompany eyelid inflammation. When squinting is marked, or comes with a cloudy or blue eye, a bulging eye or reluctance to open the eye, it more often reflects pain in the eye itself, such as a corneal ulcer, uveitis or glaucoma, and these conditions can damage sight within hours to days.

Later signals

Thickening or swelling of the eyelid

The eyelid tissue may become visibly enlarged or feel firmer to the touch. Persistent inflammation can cause oedema and fibrosis, altering the normal contour of the lid.

Hair loss around the eyelids

The skin surrounding the eye may lose hair, either from chronic rubbing or from inflammation that damages the hair follicles. The exposed skin may appear scaly or hyperpigmented.

Purulent or coloured discharge

Discharge may change from clear or mucoid to thicker yellow or green material. This can reflect secondary bacterial infection, but thick yellow-green discharge is also a feature of dry eye (keratoconjunctivitis sicca) and of inflammation without infection. The discharge may dry onto the lashes and surrounding fur, and the odour may become more noticeable.

Visible ulceration or erosion of the eyelid margin

In more severe or prolonged cases, the eyelid edge may develop small ulcers or lose its smooth contour. This can occur with deep infection, immune-mediated attack on the tissue, or chronic mechanical trauma.

Click to read about the biological mechanisms

How this is usually investigated

Investigation typically begins with a detailed history: when the signs started, whether one or both eyes are affected, any recent changes in environment or diet, and whether the dog has other skin or systemic conditions. The veterinary surgeon examines the eyelids and surrounding structures, looking at the pattern of redness, the nature of any discharge, the condition of the eyelid margins and lashes, and the position of the lids relative to the globe. From this initial picture, targeted tests may be used to identify infectious organisms, assess for underlying allergic or immune-mediated disease, or clarify anatomical contributions.

Physical examination

Purpose: A systematic look at the eyelids, conjunctiva, cornea, and surrounding facial skin helps distinguish localised eyelid inflammation from broader ocular or dermatological disease, and may reveal anatomical abnormalities such as entropion, ectropion, or eyelid masses.
Considerations: The examination provides initial clues to pattern and severity, but cannot on its own distinguish between infectious, allergic, and immune-mediated causes, or identify the specific organism or allergen involved.

Cytology

Purpose: A sample taken from the eyelid margin or any discharge is spread onto a slide and stained, allowing the veterinary surgeon to look for bacteria, yeast, inflammatory cells, or abnormal cell populations. The types and proportions of cells present can point towards infection, allergy, or neoplasia.
Considerations: Cytology is quick and can be performed during the consultation, but it shows what is present at that moment rather than explaining why it is there, and some samples yield equivocal or mixed findings that require further investigation.

Bacterial culture and sensitivity

Purpose: When bacterial infection is suspected, a swab from the eyelid margin or an expressed meibomian gland can be cultured to identify the organism and determine which antimicrobials it responds to, guiding treatment choices in cases that do not resolve with initial therapy.
Considerations: Culture takes several days to yield results, and the presence of an organism does not always mean it is the primary cause. Some bacteria are normal skin inhabitants that proliferate secondarily when the eyelid environment is already disrupted.

Histopathology

Purpose: A biopsy of the eyelid tissue, examined under the microscope, reveals the cellular architecture and the type of inflammatory infiltrate, helping to distinguish immune-mediated conditions, neoplasia, or unusual infectious agents from more common bacterial or allergic causes.
Considerations: Biopsy requires local or general anaesthesia and leaves a small wound that must heal on a mobile, sensitive structure. It is typically reserved for cases that do not respond to standard treatment or where the clinical picture suggests a process that can only be identified from the tissue itself.

Allergy testing

Purpose: Intradermal or serum testing for environmental allergens may be considered when blepharitis appears to be one manifestation of broader allergic skin disease, helping to identify specific triggers that might be modified or used to formulate desensitisation therapy.
Considerations: Allergy testing does not diagnose blepharitis itself, and positive results show sensitisation rather than proving that a given allergen is driving the current signs. The value of testing depends on whether the results will change the management plan in a way that suits the owner and dog.

Skin scraping and trichogram

Purpose: In a trichogram, hairs are plucked from the eyelid margin and examined in oil under the microscope. A trichogram or a skin scraping allows direct visualisation of Demodex mites, a common cause of periocular hair loss and blepharitis in young dogs. This test is straightforward to perform during a consultation and is typically tried before culture or biopsy are considered.
Considerations: A trichogram is often better tolerated than a deep skin scrape on the delicate eyelid skin and is particularly useful in this location, though a negative result does not fully exclude Demodex and may be followed by a deeper scrape. Mites can also be found in low numbers as normal residents of the skin, so their presence is interpreted alongside the clinical picture.

Options & trade-offs

Management is usually a combination of approaches tailored to the underlying cause, the severity of signs, and what the owner and dog find workable over time. Infectious blepharitis may respond to a relatively short course of treatment, while immune-mediated or anatomically driven forms often require ongoing attention. Different dogs and households find different balances between medication, environmental adjustment, and monitoring acceptable.

Topical antimicrobial or anti-inflammatory therapy

Ointments or drops containing antibiotics, antifungals, or corticosteroids are applied directly to the eyelid margins. Antibiotics target bacterial overgrowth, while corticosteroids dampen the inflammatory cascade; some preparations combine both. Frequency and duration vary depending on the response and the nature of the condition.

Trade-offs: Topical treatment acts locally with minimal systemic exposure, but requires regular handling of the face, which some dogs tolerate poorly. Corticosteroids applied to an eye with a corneal ulcer can stop the ulcer healing and allow it to deepen, sometimes until the cornea softens ('melts') or perforates, so the cornea is usually stained with fluorescein dye to rule out an ulcer before steroid-containing drops or ointments are started.

Systemic medication

Oral antibiotics, antifungals, antihistamines, or immunosuppressive drugs may be used when the eyelid inflammation is part of a broader skin or immune-mediated condition, or when topical therapy alone does not control signs. Where demodicosis needs treatment, it is usually treated with a product authorised in the UK for demodicosis in dogs, such as an oral isoxazoline (for example afoxolaner or fluralaner) or a spot-on combining moxidectin and imidacloprid, in which the moxidectin is absorbed through the skin. Mild localised demodicosis in young dogs often clears without treatment. The choice and duration depend on the suspected or confirmed underlying cause and the dog's response.

Trade-offs: Systemic drugs reach all tissues, which can be helpful when multiple sites are affected, but also bring the possibility of side effects elsewhere in the body. Long-term immunosuppression requires monitoring for secondary infection or other complications, and not all owners find daily oral medication practical over extended periods.

Eyelid hygiene and warm compresses

Gentle cleaning of the eyelid margins with sterile saline, or with an antiseptic at a strength suitable for use around the eye, removes crusts, debris, and surface bacteria, while warm compresses can help soften blocked meibomian gland secretions and improve drainage. This approach is often used alongside other treatments, particularly in chronic cases.

Trade-offs: Hygiene measures are low-risk when saline or an antiseptic preparation suitable for the eye is used; some antiseptics, including chlorhexidine and skin-scrub formulations, can damage the cornea. The measures can be carried out at home, but they require time and a cooperative dog. They tend to reduce discomfort and discharge rather than resolve the underlying inflammation on their own, and their benefit is most apparent when maintained regularly.

Surgical correction of anatomical abnormalities

When entropion, ectropion, or other eyelid malformations contribute to chronic irritation, surgical reshaping of the eyelid can restore normal positioning and reduce mechanical trauma to the eye surface and surrounding skin. The procedure is usually performed under general anaesthesia.

Trade-offs: Surgery can address the structural cause and reduce the risk of recurrent inflammation in anatomically predisposed dogs, but it carries the risks inherent in anaesthesia and wound healing on a mobile structure. It is most useful when the anatomical defect is clearly identified and other causes of inflammation have been ruled out or controlled.

Management of underlying systemic or skin disease

When blepharitis occurs as part of generalised allergic dermatitis, hypothyroidism, or immune-mediated skin disease, addressing the broader condition, through allergen avoidance, thyroid supplementation, or systemic immunomodulation, may reduce eyelid inflammation as the skin elsewhere improves.

Trade-offs: This approach can reduce the risk of repeated flares by treating the root process, but it requires accurate diagnosis of the systemic condition and may involve long-term medication or lifestyle change. The eyelid signs may lag behind improvement in other areas, and some dogs continue to need localised eyelid care even as the broader disease is controlled.

Common misconceptions

Misconception:

"Red, swollen eyelids always mean an eye infection that needs antibiotic drops."

Reality:

Eyelid inflammation can arise from allergy, immune activity, anatomical factors, or Demodex mites, as well as bacterial infection, and not all cases respond to antibiotics. Cytology, a skin scraping or trichogram, culture, or biopsy may be needed to identify the cause, and treatment is then directed accordingly, sometimes with an antiparasitic treatment, corticosteroids, or other anti-inflammatory drugs rather than antimicrobials.

Misconception:

"Once the eyelids look normal again, the problem is cured and treatment can stop."

Reality:

Some forms of blepharitis, particularly those linked to chronic allergy or immune-mediated disease, follow a relapsing course and may flare again if treatment is withdrawn too quickly. The duration and tapering of therapy are often guided by the underlying cause and the individual dog's pattern of response.

Misconception:

"Blepharitis is always a minor, cosmetic issue."

Reality:

While mild cases may cause only transient discomfort, untreated or chronic blepharitis can lead to persistent pain, secondary corneal damage from abnormal tear film or eyelid position, and progressive scarring that alters eyelid function. Early investigation and tailored management can reduce the risk of these longer-term changes.

Related conditions

Conjunctivitis

Conjunctivitis and blepharitis often occur together, as inflammation of the conjunctiva, the tissue lining the eyelids and covering the white of the eye, can spread to involve the eyelid margin itself, and conversely, eyelid inflammation can irritate the adjacent conjunctival tissue. In many cases, discharge and redness affect both structures simultaneously.

Atopic Dermatitis in Dogs

Atopic dermatitis can manifest as eyelid inflammation in some dogs, because the skin of the eyelids may be affected by the same allergic hypersensitivity that drives itch and inflammation elsewhere on the body. Dogs with environmental allergies may rub at the face and eyes, and the eyelid skin can become thickened, reddened, or secondarily infected.

Entropion

Entropion, inward rolling of the eyelid, can lead to secondary blepharitis, as the constant contact between fur, skin, and the eye surface irritates the eyelid margin and may introduce bacteria or cause chronic inflammation. The mechanical irritation from the malpositioned lid often requires addressing the underlying anatomy to resolve the eyelid inflammation.

Flea Allergy Dermatitis

In dogs, flea allergy dermatitis mainly affects the lower back, tail base and backs of the thighs, and the face and eyelids are involved much less often. The hypersensitivity to flea saliva can produce eyelid redness, crusting, and hair loss that resembles other causes of blepharitis.

Distichiasis

Distichiasis, extra eyelashes growing from abnormal sites along the eyelid margin, can cause chronic irritation and secondary blepharitis, as the aberrant hairs may rub against the conjunctiva and cornea, prompting discharge, redness, and inflammation of the eyelid itself. Where the extra lashes are causing the irritation, managing them is often needed to resolve the eyelid inflammation.

Two points shape how blepharitis is investigated: whether the signs are confined to the eyes or also affect the skin elsewhere, and whether they form a single episode or a recurring cycle. A record of when flares occur, what the eyelids look like between episodes and any changes in environment or routine adds detail to the clinical picture. For dogs with broader skin or immune conditions, the eyelid signs often sit within a larger context that shapes the overall management approach.

Last reviewed: 9 October 2026 · Dr Alastair Greenway MRCVS