Why Is My Dog Squinting? Possible Causes and What to Do
Squinting in dogs is a visible sign that something may be affecting one or both eyes, ranging from mild irritation to conditions that require prompt veterinary attention.
Quick Answer
Dog squinting can be caused by foreign bodies, dry eye, allergies, corneal ulcers, infections, or glaucoma. Mild, short-lived squinting without other signs may resolve on its own, but persistent squinting, redness, discharge, or pawing at the eye should be evaluated by a veterinarian promptly.
SYMPTOM TRIAGE
Not sure how serious your dog's squinting is? Use our free symptom triage tool to get a preliminary assessment and guidance on next steps.
What Dog Squinting Looks Like
Squinting, medically referred to as blepharospasm, is the partial or complete involuntary closure of one or both eyelids. In dogs, this can appear as a persistent half-closed eye, frequent blinking, or a tight narrowing of the eye opening. You may also notice your dog avoiding bright light or rubbing its face against furniture or carpet.
Squinting differs from the relaxed, slow blink that some dogs display in calm settings. A dog that is squinting due to discomfort typically holds the eye in a narrowed position for extended periods and may show additional signs such as pawing at the face, excessive tearing, or visible redness of the eye or surrounding tissue.
It is important to observe whether the squinting affects one eye (unilateral) or both eyes (bilateral). Unilateral squinting is more commonly associated with a localized issue such as a scratch, foreign body, or ulcer in one eye. Bilateral squinting may point to systemic or environmental factors such as allergies, dry eye syndrome, or an underlying condition affecting both eyes.
Possible Causes Associated with Squinting
Several conditions may cause a dog to squint. The following are among the most commonly reported.
Foreign Body. Grass awns, seeds, dirt, sand, or small debris can become lodged in the eye or under the third eyelid. This is one of the most frequent causes of acute squinting, particularly in dogs that spend time outdoors in grassy or wooded areas. The dog may paw at the affected eye or rub its face along the ground.
Corneal Ulcer. A scratch or abrasion on the clear outer layer of the eye (the cornea) can cause significant discomfort and squinting. Corneal ulcers may result from trauma, contact with a foreign body, or rubbing. Deep ulcers can progress quickly and may lead to vision loss if left untreated.
Dry Eye (Keratoconjunctivitis Sicca). This condition occurs when the tear glands do not produce enough tears to keep the eye lubricated. Chronic dryness can lead to inflammation, squinting, thick discharge, and over time, damage to the cornea. Certain breeds, including Cavalier King Charles Spaniels, Shih Tzus, and West Highland White Terriers, may be predisposed.
Allergies. Environmental allergens such as pollen, dust mites, and mold can cause eye irritation in dogs. Allergic conjunctivitis may present with squinting, redness, watery discharge, and itchiness affecting both eyes simultaneously.
Conjunctivitis. Inflammation of the conjunctiva, the mucous membrane lining the eyelids and covering the white of the eye, can be caused by infections (bacterial or viral), allergens, or irritants. Signs often include squinting, redness, and discharge that may be clear, yellow, or greenish.
Glaucoma. Elevated pressure inside the eye can cause pain and squinting. Glaucoma is considered a medical emergency because rapid pressure increases can lead to permanent vision loss. Breeds such as Cocker Spaniels, Basset Hounds, and Arctic breeds may have a higher risk.
Entropion. This is a structural condition in which the eyelid rolls inward, causing the eyelashes to rub against the surface of the eye. Entropion can lead to chronic irritation, squinting, and corneal damage. It is more commonly seen in breeds with loose facial skin, such as Shar-Peis and Bulldogs.
What to Monitor at Home
If you notice your dog squinting, there are several observations that can help your veterinarian determine the likely cause and urgency.
- Duration: How long has the squinting been present? A sudden onset that persists for more than a few hours warrants closer attention.
- Discharge: Note the color and consistency of any eye discharge. Clear, watery discharge may be associated with allergies or mild irritation. Thick yellow or green discharge may suggest infection.
- Redness and Swelling: Check whether the white of the eye appears red or bloodshot and whether the tissues around the eye are swollen.
- Pawing and Rubbing: Frequent pawing at the eye or face rubbing increases the risk of further corneal damage and is a sign of discomfort.
- Changes in Behavior: A normally active dog that becomes withdrawn, reluctant to open curtains, or sensitive to light may be experiencing significant eye pain.
- Appetite and Energy: Loss of appetite or reduced activity accompanying squinting may indicate a more systemic issue.
What to Do
Do not attempt to examine the eye by holding the eyelids open forcefully. This can cause further injury, especially if a foreign body or ulcer is present.
- Flush the eye gently with sterile saline solution if you suspect a mild irritant such as dust.
- Prevent your dog from pawing at the eye by using an Elizabethan collar (cone) if necessary.
- Avoid applying any human eye drops, ointments, or home remedies without veterinary guidance.
- Note all observations and bring them to your veterinary appointment.
- Schedule a veterinary examination if squinting persists for more than a few hours or is accompanied by any of the signs listed above.
When to Contact a Veterinarian
Contact a veterinarian promptly if you observe any of the following:
- Squinting that persists for several hours without improvement
- Visible foreign material in or around the eye
- Redness, swelling, or cloudiness of the eye
- Yellow, green, or thick discharge from the eye
- Pawing, rubbing, or signs of significant pain
- Sensitivity to light or reluctance to open the eye in normal lighting
- A bulging or changed appearance of the eyeball
- Squinting accompanied by lethargy, loss of appetite, or other systemic signs
If your veterinarian is unavailable and any of the above signs are severe or worsening, seek emergency veterinary care.
Frequently Asked Questions
Can allergies cause my dog to squint?
Yes. Allergic reactions to pollen, dust, mold, or other environmental allergens can cause inflammation and irritation of the conjunctiva, leading to squinting, redness, and watery discharge in one or both eyes.
Should I use human eye drops on my squinting dog?
No. Human eye drops may contain ingredients that are not safe for dogs or may worsen certain eye conditions. Always consult a veterinarian before applying any medication to your dog's eyes.
Can a corneal ulcer heal on its own?
Superficial corneal abrasions may heal with veterinary treatment and proper care, but deeper ulcers require medical intervention. Untreated ulcers can deepen, become infected, and lead to permanent scarring or vision loss.
Why is my dog squinting only one eye?
Unilateral squinting is often associated with a localized problem in one eye, such as a foreign body, corneal ulcer, or scratch. Bilateral squinting may suggest a broader issue such as allergies or dry eye.
Concerned about your dog's symptoms?
Our free symptom triage tool can help you assess the urgency and determine the best next steps for your pet.
Sources
- American College of Veterinary Ophthalmologists (ACVO)
- American Veterinary Medical Association (AVMA)
- Cornell University College of Veterinary Medicine
- The Royal Veterinary College (RVC), University of London
- Veterinary Ophthalmology, 6th Edition (Gelatt et al.)
Disclaimer
This article is for informational purposes only and does not constitute veterinary advice. PawAI Lab does not diagnose, treat, or prescribe for any animal health condition. If your dog is experiencing a health concern, consult a licensed veterinarian. In case of an emergency, contact your nearest veterinary emergency service immediately.