Updated November 1, 2026. Fact-checked against veterinary sources; review by a licensed veterinarian is in progress. See our editorial policy.
A little discharge at the corner of a dog’s eye after sleep can be harmless, but a painful eye is different. Dogs often squint, rub their face or hold an eye partly closed instead of obviously crying. Because problems such as corneal ulcers and glaucoma can damage vision quickly, it is safer to arrange an examination than to try leftover drops.
Eye symptoms that cannot wait
Seek same-day or emergency veterinary care if your dog suddenly cannot open an eye, has marked squinting, a cloudy or bluish cornea, visible injury, bleeding, a rapidly swollen eye, sudden blindness or an eye that appears enlarged or bulging. Eye problems accompanied by a head injury or severe systemic illness also need urgent attention. If a chemical splashes into the eye, contact an emergency veterinarian immediately for flushing instructions.
When discharge or redness needs an appointment
Persistent yellow or green discharge, recurring watery eyes, redness, rubbing, or swelling around the eyelids should be assessed promptly. Allergies may contribute to irritation, but dry eye, abnormal eyelid position, infected tissue, a foreign object and scratches can look similar. A dog’s eyes can be uncomfortable even without dramatic discharge.
What the veterinarian may test
A clinician may use a fluorescein stain to look for damage to the cornea, check tear production and measure eye pressure when appropriate. These tests help distinguish conditions that require very different treatments. A steroid-containing eye medication, for example, can be dangerous when a corneal ulcer is present. Do not use human redness-relief drops or medication left from another pet.
Practical care while arranging the visit
Prevent rubbing with an appropriately fitted protective collar if available and safe. Keep your dog away from dust and rough play. Do not pry the eye open or try to remove an embedded object. You can gently wipe crust from the surrounding fur with clean damp gauze, without pressing on the eyeball.
How this connects to prevention
Some eye injuries can be reduced by trimming obstructive facial hair under safe guidance and avoiding thorny vegetation, but inherited conditions or dry eye are not entirely preventable. For everyday precautions, see our guide to caring for canine eyes. This article does not replace an eye examination.
References
Merck Veterinary Manual, eye disorders in dogs; Merck: When to See a Veterinarian.
This article is for general education and is not a substitute for care from your own veterinarian. Learn about The Pet Vet and our editorial policy.