Most dog owners notice some eye crust in the morning and wonder: is this normal or something to worry about? The answer depends entirely on the colour, consistency, volume, and whether it comes with other symptoms.
This guide breaks down the 5 most common causes of dog eye discharge — from completely harmless to requiring same-day veterinary attention.
What Is Normal Eye Discharge in Dogs?
A small amount of clear or brownish crust at the inner corner of your dog's eye each morning is normal. This is dried tear film — equivalent to the "sleep" humans get overnight. It wipes away easily with a damp cloth. If this is all you see, no action is needed.
The rule of thumb: If the discharge is clear or light brown, easily wiped away, and your dog is comfortable (no squinting, pawing, or redness), it is normal. Any other colour, consistency, or accompanying discomfort requires assessment.
5 Conditions That Cause Abnormal Eye Discharge
Conjunctivitis (Bacterial or Viral) Monitor
The most common cause of abnormal eye discharge in Indian dogs. Bacterial conjunctivitis produces yellow-green, thick discharge that often causes the eyelids to stick together in the morning. Viral conjunctivitis tends to produce clearer, more watery discharge with obvious eye redness.
What to look for: Yellow-green pus, red or swollen conjunctiva (the membrane lining the eyelid), squinting, and frequent blinking. Often affects one eye first before spreading to the other.
What to do: See a vet within 48 hours. Bacterial conjunctivitis is treated with topical antibiotic eye drops (chloramphenicol or tobramycin). Do not use human eye drops — the concentrations differ. Gently clean the discharge with a separate cotton ball per eye to avoid cross-contamination.
Dry Eye — Keratoconjunctivitis Sicca (KCS) Monitor
Dry eye occurs when the lacrimal glands fail to produce adequate tear film. Without lubrication, the corneal surface dries out and the body produces a stringy, mucus-like grey or white discharge as a compensatory mechanism. This is a chronic condition that worsens over time if untreated.
What to look for: Thick, grey-white, ropy discharge (not watery). Dull, hazy, or slightly bluish cornea. Frequent blinking or squinting. The eye may look dry or have reduced "sheen". Common in Pugs, Shih Tzus, Bulldogs, Cocker Spaniels, and Lhasa Apsos.
What to do: See a vet promptly — KCS is a chronic disease requiring lifelong management with cyclosporine or tacrolimus eye drops to stimulate tear production. Artificial tears provide temporary relief but do not treat the underlying deficiency. Untreated KCS leads to corneal scarring and vision impairment.
Not sure if it's conjunctivitis or dry eye?
PawCheck's eye scanner analyses a photo of your dog's eye and gives you a severity result — Normal, Monitor, or Urgent — in under 10 seconds.
Get Early Access — Free →Glaucoma Urgent
Glaucoma is a build-up of intraocular pressure (IOP) that damages the optic nerve. It is one of the most urgent eye conditions in dogs because blindness can occur within 24–72 hours of a pressure spike. Eye discharge in glaucoma is usually a secondary finding — the primary signs are more alarming.
What to look for: A visibly enlarged or bulging eyeball. Cloudy or bluish cornea. The dog pawing urgently at the eye, extreme redness of the sclera (white of the eye), and apparent pain (head pressing, reluctance to move). Watery discharge is incidental.
What to do: This is a veterinary emergency. Go to a clinic same day. Glaucoma is managed with IOP-lowering eye drops (dorzolamide, latanoprost) or surgery. Once vision is lost it cannot be recovered — early intervention is the only way to preserve sight.
Entropion — Eyelid Rolling Inward Monitor
Entropion is a structural defect where the eyelid margin rolls inward, causing the eyelashes to rub continuously against the corneal surface. This produces chronic irritation, tearing, and secondary infection. It is common in Chow Chows, Shar Peis, Bulldogs, Labrador Retrievers, and Rottweilers.
What to look for: Constant tearing with brown staining below the eye (epiphora). The dog squinting or holding one eye partially closed. Visible inward rolling of the lower or upper eyelid when you look closely. The cornea may appear cloudy from chronic friction.
What to do: See a veterinary ophthalmologist. Mild cases in puppies are managed with eyelid tacking (temporary stitches) while the face matures. Persistent entropion requires corrective surgical repair (blepharoplasty) — this is a common, effective procedure.
Blocked Tear Duct (Epiphora) Monitor
The nasolacrimal duct (tear duct) drains tears from the eye into the nasal passage. When blocked, tears overflow continuously onto the face, causing chronic brown-red staining of the fur below the eye, particularly visible in light-coloured dogs. This is very common in toy breeds and brachycephalic (flat-faced) breeds.
What to look for: Persistent brown or reddish-brown staining in the tear-stain region below the eye. No eye redness, swelling, or discharge at the eye itself — the overflow is clear. The dog is otherwise comfortable.
What to do: A vet can confirm a blocked duct with a fluorescein stain test. Treatment varies: flushing under sedation clears debris; chronic cases may need surgical stent placement. For cosmetic tear staining, gentle daily cleaning with saline keeps it manageable.
When to go to the vet — quick guide
- Same day: Cloudy cornea, bulging eye, dog pawing urgently at eye, suspected glaucoma
- Within 48 hours: Yellow-green discharge, swollen eyelids, both eyes affected, discharge increasing
- Within the week: Stringy grey discharge (possible KCS), chronic tearing with staining, squinting without redness
- No action needed: Small amount of clear/brown morning crust, dog fully comfortable
Over-the-counter human eye drops (Visine, Optrex, etc.) contain preservatives and vasoconstrictors at concentrations that are harmful to dogs. Always use veterinary-prescribed formulations. If in doubt, saline rinse is the only safe interim measure.