Dog Eye Discharge: What Each Color Means

Eye discharge is common in dogs — but the color, consistency, and whether it affects one or both eyes tells you a lot about the cause.

What Normal Eye Discharge Looks Like

Small amounts of clear or slightly grey-brown crust in the inner corner of the eye, especially in the morning. This is normal tear drainage and debris. Easily wiped away. Both eyes equally affected.

Discharge Colors and What They Mean

Clear, Watery Discharge

Causes: Allergies (environmental), irritants (dust, wind, smoke), blocked tear duct, corneal irritation, or a foreign body. Watery eyes that come and go seasonally = allergies. Watery eyes that started suddenly = possible foreign body or injury.

White or Grey Discharge

Causes: Dry eye (keratoconjunctivitis sicca or KCS), where the tear glands don't produce enough tears. The body produces thick mucus instead. Common in certain breeds (Cavalier King Charles Spaniel, Cocker Spaniel, Westie). Untreated KCS leads to corneal scarring and blindness.

Yellow or Green Discharge

Causes: Bacterial infection (conjunctivitis), corneal ulcer, or injury. Thick green/yellow discharge = white blood cells fighting infection. THIS REQUIRES VETERINARY ATTENTION. Do not use leftover eye medications from a previous infection.

Bloody or Red Discharge

Causes: Trauma, corneal ulcer, glaucoma, or tumor. Emergency — see a vet or ophthalmologist immediately.

One Eye vs. Both Eyes

One eye affected: Foreign body, injury, corneal ulcer, localized infection. Check for a grass seed, splinter, or scratch.

Both eyes affected: Systemic cause — allergies, infection, dry eye, or anatomical issue (entropion where eyelids roll inward).

When It's an Emergency

Go now: Sudden onset of squinting or holding the eye closed, eye looks cloudy or blue, visible object in the eye, bleeding from the eye, dog rubbing eye violently, eye suddenly bulging (glaucoma — causes permanent blindness within hours).

Schedule vet visit: Green or yellow discharge, discharge lasting more than 2 days, discharge + redness/swelling, any change in vision.

Monitor at home: Small amount of clear discharge in both eyes with no redness or squinting.

What NOT to Do

Do not use human eye drops, do not use leftover pet medications, do not wipe with anything other than a clean damp cloth, do not try to remove a visible object from the eye yourself.