If Your Dog Is Squinting — Suspect Corneal Injury and Signs to Seek Veterinary Care

Eye HealthSymptomsMeongsiljang Veterinary Advisory Board

When your dog squints or keeps its eyes partially closed, it’s a sign that something may be wrong with its eyes. Here’s a step-by-step guide to handling the issue based on the cause, along with clear indicators for when to seek immediate veterinary care.

Is Your Dog Squinting? What to Check Right Now

When a dog squints, it’s often a sign of pain, irritation, or inflammation in the eye, causing them to keep their eyes partially closed or half-lidded. The most important thing to remember is not to dismiss it as mere tiredness. If your dog suddenly squints one eye, or if you notice tearing, discharge, or redness, it’s safest to visit a veterinary clinic within 24 hours. While the cause might be something minor like a foreign object, it could also be a rapidly worsening condition such as a corneal ulcer or glaucoma.

Step-by-Step Guide to Handling Squinting by Severity

Item	Main symptoms	Recommended action
Stage 1 (Mild)	Occasional squinting, slight tearing, clear eye	Observe for 4–6 hours
Stage 2 (Moderate)	Frequent squinting, increased discharge/tearing, redness	See a vet within 24 hours
Stage 3 (Severe)	Eye kept closed, cloudy cornea, swollen eye	See a vet immediately
Emergency	Bulging eye, severe pain, suspected vision loss	Go to an emergency vet immediately

If it's hard to tell the stages apart, use 'how often and how long the squinting lasts' as your guide.

Checklist of Accompanying Symptoms

If your pet squints along with any of the following symptoms, it may indicate different underlying causes:

Excessive tearing or eye discharge: This could be due to conjunctivitis, corneal irritation, or a blocked tear duct.

Red, bloodshot eyes: Commonly seen in conjunctivitis, uveitis, or glaucoma.

Cloudy cornea: May indicate a corneal ulcer or edema — this is an emergency.

Rubbing the eye with the paw: A sign of significant pain or itching.

Squinting with only one eye: Often caused by a foreign object, injury, or infection affecting just one eye.

Close-up of a puppy’s eye with discharge and redness

Signs You Need to Go to an Emergency Veterinary Clinic Immediately

If any of the following signs are present, do not wait at home—seek veterinary care immediately. Corneal ulcers, glaucoma, and uveitis can cause vision loss within hours. • The eye appears larger than normal or bulging • The cornea (the clear front surface of the eye) looks cloudy or white • The eye is completely closed and the pet refuses to open it • Severe swelling around the eye • Extreme pain when attempting to touch the eye

Causes of Squinting — Surface Eye Issues

The most common causes originate on the surface of the eye. Foreign bodies (sand, grass seeds, eyelashes): If your pet suddenly squints after a walk, suspect a foreign body. Rubbing the eye can scratch the cornea. Corneal abrasions and ulcers: These occur from scratches or eyelash pricks. They can only be confirmed with a corneal stain test. Conjunctivitis: Caused by viruses, bacteria, or allergies. Yellowish eye discharge is characteristic. Keratoconjunctivitis sicca (dry eye): Insufficient tear production leaves the cornea dry and irritated. Thick, mucoid discharge is characteristic.

A puppy getting an eye exam at the veterinary clinic

Causes of Squinting — Internal and Structural Eye Issues

If symptoms are severe or persist, the issue may lie within the eye itself.

Glaucoma: This condition arises from increased intraocular pressure and often has a genetic predisposition. It typically develops rapidly within hours, causing corneal edema (cloudy swelling of the cornea), conjunctival hyperemia (redness of the white part of the eye), and squinting due to severe pain. The pupil may dilate or constrict, and rapid progression can lead to blindness. In chronic cases, the eye may appear progressively enlarged.

Uveitis: This is an inflammatory condition affecting the uvea, the inner layer of the eye. It can result from various causes, including trauma, systemic diseases, or infections. Signs may include miosis (constricted pupils) or asymmetry between the two eyes.

Entropion: This structural abnormality occurs when the eyelid rolls inward, causing the eyelashes to constantly rub against the cornea. It is common in certain breeds and can lead to recurrent corneal irritation and ulcers, often requiring surgical correction.

Cherry Eye (Third Eyelid Prolapse): When the gland of the third eyelid prolapses outward, it appears as a red mass and causes ocular irritation.

What You Can Do at Home — Do Only This

It’s important to know what you can and cannot do before visiting the clinic. ✅ What you can do • Gently wipe away eye discharge around the eyes using preservative-free sterile saline. • If you see a foreign object inside the eyelid, flush it out with saline. • Fit your pet with an Elizabethan collar (E-collar) to prevent them from rubbing their eyes. ❌ What you should not do • Do not touch the inside of the eye directly with cotton swabs or your fingers. • Do not apply antibiotic eye drops without a prescription. • If symptoms are stage 2 or higher, do not wait more than two days at home before seeking care.

A pet owner gently wiping their dog’s eye area with saline solution

Brachycephalic and Proptotic Breeds Require Extra Caution

Brachycephalic breeds with flat faces and prominent eyes, such as Pugs, Shih Tzus, Pekingese, and French Bulldogs, have a larger exposed corneal surface area due to their anatomy. This makes them more prone to corneal injuries compared to other breeds, and their eyelids may not close completely, leading to increased dryness. In these breeds, even slight squinting should prompt immediate evaluation for potential corneal ulcers. Observing symptoms at home for several days can be risky.

Diagnostic and Treatment Process at the Veterinary Clinic

To identify the cause of squinting, veterinary clinics perform a variety of diagnostic tests.

Corneal staining test: This is the most critical test for determining whether a corneal ulcer is present.

Slit-lamp examination: This allows for a magnified view of the cornea, conjunctiva, and anterior segment of the eye.

Intraocular pressure measurement: This checks for glaucoma.

Tear production test: This assesses for dry eye (keratoconjunctivitis sicca).

Depending on the underlying cause, treatments may include antibiotic eye drops, anti-inflammatory eye drops, artificial tears, or medications to lower intraocular pressure. Using these medications without a veterinarian’s diagnosis can worsen the condition.

Reviewed by a veterinarian

Dr. Tony — Punnawat Phongkittirak

Veterinarian

A veterinarian who majored in veterinary medicine at Khon Kaen University, Thailand, and completed the IVSA program at North Carolina State University in the United States. Drawing on clinical experience at animal hospitals, he works in the pet healthcare field and is dedicated to building a digital care environment that connects pet parents with veterinarians.

Frequently Asked Questions

My dog is squinting, but there’s no eye discharge. Is that okay?

Even without visible eye discharge, your pet may still be experiencing pain. Conditions such as corneal abrasions or early-stage glaucoma can cause squinting without any discharge. If these symptoms persist for more than a day, it is advisable to visit the clinic.

My pet suddenly squints after a walk. Could something have gotten in their eye?

It’s quite likely. Gently flush the eye with preservative-free sterile saline. If there’s no improvement within 30 minutes, you should visit the clinic. A foreign body may have scratched the cornea.

Can I use human artificial tears for my pet?

It’s best to avoid them. Human artificial tears often contain preservatives that can irritate your dog’s cornea. Until you see the vet, simply rinse the outside of the eye with preservative-free saline solution.

My pet squints with only one eye. Is it more serious when the eyes look different?

If your pet is squinting with only one eye, it could be due to trauma, a foreign object, or an infection affecting just that eye. If both eyes are squinting, it might indicate a systemic illness or severe allergies. In either case, if the squinting persists for more than 24 hours, you should visit the vet.

Does entropion require surgery?

If the eyelids turn inward, causing the eyelashes to constantly rub against the cornea, surgical correction is necessary. Left untreated, this can lead to recurrent corneal ulcers and potentially impair vision. Your veterinarian will determine the best course of action after a thorough examination.

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References

[1] Maggs DJ, Miller PE, Ofri R. Slatter's Fundamentals of Veterinary Ophthalmology. 6th ed. Elsevier; 2017.

[2] Ettinger SJ, Feldman EC, Côté E. Textbook of Veterinary Internal Medicine: Diseases of the Dog and the Cat. 8th ed. Elsevier; 2017.

[3] Brooks DE, Plummer CE. Clinical Atlas of Canine and Feline Ophthalmic Disease. 2nd ed. Wiley-Blackwell; 2022.

[4] Nelson RW, Couto CG. Small Animal Internal Medicine. 6th ed. Elsevier; 2019.