Dog Squinting One Eye: Causes, Urgency, and Next Steps

TL;DR: Squinting in dogs indicates ocular pain and is a medium-urgency condition that requires a veterinary exam within 24 hours to prevent permanent damage. Seek emergency care immediately if you notice cloudiness, bulging, or sudden vision loss.

What does it mean when my dog is squinting or holding its eye shut?

• Squinting, medically known as blepharospasm, is an involuntary eyelid contraction that indicates ocular pain.
• It serves as a major red flag that the eye’s surface or internal structures are irritated.
• Common causes include corneal ulcers (scratches), foreign objects like hair or grass seeds, and internal inflammation like uveitis.

Is my dog's squinting a veterinary emergency?

• Squinting is classified as a Medium Urgency situation; while not always life-threatening, eye conditions can deteriorate into deep infections or perforations within 24 to 48 hours.
• You should contact a veterinarian for an appointment within the same day.
• Seek emergency care immediately if squinting is accompanied by a change in eye color, a bulging appearance, or sudden blindness.

How does a photo of my dog's eye help with veterinary triage?

• A clear image allows the vet to identify markers such as discharge type (clear vs. yellow/green) and visible debris.
• Photos help professionals assess corneal cloudiness and differences in pupil size.
• Because dogs often clamp their eyes shut when stressed at the clinic, a photo taken at home provides a more natural look at the irritation's severity.