A small amount of discharge in a dog’s eye is completely normal — just like humans, dogs produce eye secretions that collect in the corner of the eye, particularly overnight. But when discharge becomes excessive, changes colour, or is accompanied by redness, squinting, or swelling, it is telling you something is wrong.
This guide covers what normal eye discharge looks like, what the different types of discharge mean, and when your dog needs the vet.
What Is Normal Dog Eye Discharge?
A small amount of clear or slightly grey crusty discharge in the inner corner of the eye after sleep is normal in most dogs. This is simply dried tears and eye secretions — the equivalent of “sleep” in human eyes.
Normal discharge:
- Small amount
- Clear, white, or slightly grey
- Found in the inner corner of the eye after sleep
- No redness, swelling, or squinting accompanying it
- Your dog is not pawing at their eye
Anything beyond this warrants closer attention.
Types of Eye Discharge and What They Mean
Clear, Watery Discharge
A constant flow of clear, watery discharge from one or both eyes suggests:
- Allergies — environmental allergens cause watery eyes alongside other signs like itching and sneezing. See our dog skin problems and itching guide for the full picture on canine allergies
- Foreign body — a grass seed, dust, or small piece of debris irritating the eye surface
- Blocked tear duct — tears overflow onto the face instead of draining normally, causing tear staining (particularly visible in white-coated breeds)
- Early conjunctivitis — inflammation of the eye’s outer membrane
Yellow or Green Discharge
This colour change is significant. Yellow or green discharge almost always indicates bacterial infection — either:
- Bacterial conjunctivitis — infection of the conjunctiva (the pink membrane lining the eyelid)
- Secondary infection following another eye condition
- Distemper — in unvaccinated dogs, eye discharge alongside respiratory and neurological signs
Yellow or green discharge requires veterinary treatment — antibiotic eye drops or ointment are needed and will not resolve without treatment.
Thick, Mucus-Like Grey or White Discharge
Thick, sticky discharge that accumulates rapidly suggests:
- Dry eye (Keratoconjunctivitis Sicca / KCS) — the most common cause of thick, mucoid discharge. The tear glands produce insufficient tears, causing the eye to compensate with excess mucus. Without treatment, dry eye causes corneal scarring and eventually vision impairment
- Conjunctivitis with secondary mucus production
Dry eye is diagnosed with a Schirmer tear test at the vet and managed with daily eye drops (cyclosporine or tacrolimus) long-term.
Brown or Reddish-Brown Discharge (Tear Staining)
Particularly common in flat-faced breeds (French Bulldogs, Pugs, Shih Tzus) and white or light-coated breeds (Bichon Frise, Maltese). The brown staining is caused by porphyrins — compounds in tears that oxidise and stain the fur when tears overflow onto the face.
Tear staining itself is cosmetic, but the underlying cause (blocked tear duct, eye shape, or chronic low-grade irritation) should be investigated.
Discharge With Redness, Squinting, or Pawing at the Eye
This combination indicates acute eye pain and requires same-day veterinary attention. Possible causes include:
- Corneal ulcer — a scratch or wound on the clear surface of the eye
- Glaucoma — increased pressure inside the eye, extremely painful
- Uveitis — inflammation inside the eye
- Foreign body embedded in the eye
Breeds Prone to Eye Discharge
Some breeds are structurally predisposed to eye problems due to their facial conformation:
Brachycephalic breeds (French Bulldogs, Pugs, Bulldogs, Shih Tzus) — their shallow eye sockets and prominent eyes are more exposed and prone to irritation, corneal injury, and tear overflow.
Breeds with loose facial skin (Basset Hounds, Bloodhounds, Saint Bernards) — drooping lower eyelids (ectropion) cause chronic eye irritation and discharge.
Breeds with inward-rolling eyelids (Chow Chows, Shar Peis, some Retrievers) — entropion causes the eyelashes to rub against the eye surface, causing discharge, pain, and corneal damage.
Long-haired breeds (Shih Tzus, Maltese, Lhasa Apso) — facial hair touching the eye surface causes chronic irritation and discharge.
When to See the Vet
See the vet same day if:
- Discharge is yellow or green
- Your dog is squinting or keeping the eye closed
- The eye looks red or inflamed
- Your dog is pawing at their eye repeatedly
- One eye looks different in size to the other
- The pupil appears cloudy or the eye surface looks dull or hazy
Book an appointment within 48 hours if:
- Discharge has increased significantly in volume
- Watery discharge has been present for more than a week
- Tear staining has appeared suddenly in a dog who did not previously have it
Monitor at home if:
- Small amount of clear discharge in the corner of the eye after sleep with no other symptoms
Home Care for Mild Eye Discharge
For normal or mildly increased clear discharge:
- Gently wipe the discharge away with a soft, damp cloth or cotton ball — always wiping away from the eye, not toward it
- Use a separate cloth for each eye to avoid transferring any infection
- Never use human eye drops unless specifically directed by your vet — many contain ingredients harmful to dogs
Do not attempt to treat yellow or green discharge at home — antibiotic eye drops require a prescription and the correct diagnosis.
Dog Eye Discharge — FAQ
My dog has brown staining under their eyes — is this a health problem? Tear staining is usually cosmetic rather than a health emergency, but the underlying cause is worth investigating. A blocked tear duct, eye shape issue, or chronic low-grade irritation can all cause it. Mention it at your dog’s next routine vet visit.
Can conjunctivitis in dogs spread to humans? Bacterial conjunctivitis in dogs is generally not contagious to humans. However, wash your hands after touching your dog’s eye area, particularly if discharge is present.
My dog’s eye is closed and has discharge — how urgent is this? A dog keeping one eye closed is in pain — this is a same-day vet visit. A closed eye with discharge suggests a corneal ulcer, foreign body, or acute infection, all of which need prompt treatment.
Can I use human eye drops on my dog? No — not without specific veterinary instruction. Some human eye drops contain preservatives or medications harmful to dogs. Saline solution can be used to gently flush debris from the eye, but medicated drops require a veterinary prescription.
My puppy has eye discharge — is this normal? A small amount of clear discharge is normal in puppies. Yellow or green discharge in a puppy needs veterinary attention — puppies are more vulnerable to infections and conditions like distemper in unvaccinated animals. Ensure your puppy’s vaccines are on schedule. See our kitten vaccine schedule guide for vaccine timing principles that apply to puppies too.
Also read: Dog Skin Problems and Itching | My Dog Is Not Eating | How to Care for a Senior Dog | Dog Anxiety — Signs, Causes and Treatments
