Quick Answer: Dog eye discharge ranges from normal (small amounts of clear or brownish crust in the corner of the eye) to concerning (green or yellow pus, excessive tearing, cloudiness, or squinting). Common causes include normal eye-cleaning secretions, allergies, dry eye (KCS), conjunctivitis, blocked tear ducts, or corneal injury. Green or yellow discharge always warrants a vet visit.
This guide is for informational purposes and does not replace veterinary diagnosis.
In This Guide:
Normal vs. Abnormal Eye Discharge
| Discharge Type | Normal or Concerning? | Likely Cause | Action |
|---|---|---|---|
| Small amount of clear/watery | Usually normal | Routine eye cleaning, mild irritation | Wipe gently, monitor |
| Brownish crust in corner (sleep) | Normal | Normal secretions, dried overnight | Wipe with warm damp cloth |
| Reddish-brown tear staining | Usually normal (cosmetic) | Porphyrin pigment in tears, blocked duct | Clean daily; vet if sudden change |
| Excessive watery tearing | Concerning | Blocked tear duct, corneal scratch, allergy | Vet evaluation recommended |
| White/grey mucus | Concerning | Dry eye (KCS), mild conjunctivitis | Vet visit recommended |
| Yellow or green pus | Always concerning | Bacterial conjunctivitis, eye infection | Vet visit promptly |
| Discharge + squinting/pawing | Urgent | Corneal injury, foreign body, ulcer | Same-day vet visit |
| Discharge + cloudy eye | Urgent | Corneal ulcer, glaucoma, uveitis | Same-day vet visit |
Source: American College of Veterinary Ophthalmologists; VCA Animal Hospitals ophthalmology guidelines
Causes of Dog Eye Discharge
- Conjunctivitis (Pink Eye): Inflammation of the conjunctiva — the membrane lining the eyelid. Can be caused by bacteria, viruses, allergies, or irritants. Signs include redness, swelling, and discharge ranging from clear to yellow-green
- Dry Eye (Keratoconjunctivitis Sicca / KCS): The eye doesn’t produce enough tears, leading to white/grey mucus discharge and chronic irritation. Common in Cocker Spaniels, Bulldogs, and Shih Tzus. Requires daily eye drops (cyclosporine or tacrolimus)
- Allergies: Seasonal or environmental allergens cause excessive watery tearing and clear discharge, often accompanied by skin itching and sneezing
- Blocked Nasolacrimal Duct: The duct draining tears into the nose becomes blocked, causing overflow tearing and brown staining. More common in brachycephalic (flat-faced) breeds
- Corneal Injury: A scratch, foreign body, or ulcer causes acute tearing, squinting, and light sensitivity — always a veterinary emergency
- Entropion: Eyelid rolls inward, causing lashes to rub against the eye — common in Shar Peis, Chow Chows, and Bulldogs. Requires surgical correction
- Epiphora: Chronic excessive tearing leading to the characteristic reddish-brown staining seen especially in white-coated breeds like Maltese and Bichon Frises
Breeds Prone to Eye Discharge
Certain breeds have structural characteristics that make eye discharge more common:
- Brachycephalic breeds (Pugs, Bulldogs, Shih Tzus, Cavaliers): Large, prominent eyes are more exposed to irritants; abnormal tear drainage is common
- Long-haired breeds (Maltese, Shih Tzu, Lhasa Apso): Hair can irritate the eye surface; regular grooming to keep hair trimmed away from eyes is essential
- Cocker Spaniels: Very high rates of dry eye (KCS)
- Bloodhounds and Saint Bernards: Droopy lower eyelids (ectropion) collect debris
- Toy breeds generally: More prone to blocked tear ducts and epiphora (tear staining)
How to Clean Dog Eye Discharge
For routine discharge and tear staining, clean gently daily:
- Use a clean, soft cloth or cotton ball dampened with warm water or sterile saline solution
- Wipe gently from the inner corner of the eye outward — never push debris deeper into the eye
- Use a fresh cloth or cotton ball for each eye to avoid cross-contamination
- For stubborn tear staining, commercial tear stain removers are available — look for products containing no bleach or harsh chemicals
- For long-haired breeds, keep hair trimmed away from the eye area — ask your groomer to trim the periocular hair at each visit. Find groomers near you
- Never use human eye drops in your dog’s eyes unless specifically recommended by a veterinarian
When to See a Veterinarian
Contact your vet if your dog has:
- Yellow or green discharge — always indicates infection requiring treatment
- Squinting or keeping one eye partially closed
- Pawing at or rubbing the eye on furniture/carpet
- Sudden increase in clear tearing (possible foreign body or scratch)
- Cloudiness, haziness, or visible change in eye appearance
- Redness that persists for more than 24 hours
- Any eye discharge in a puppy under 3 months
Find a veterinary clinic near you for prompt eye evaluation.
Frequently Asked Questions
What causes dog eye discharge?
Dog eye discharge can be caused by normal eye secretions, environmental allergies, conjunctivitis (bacterial or viral), dry eye (KCS), blocked tear ducts, corneal injuries, foreign bodies, or structural eye issues in certain breeds. Small amounts of clear discharge or brownish crust in the corner are usually normal. Yellow or green discharge, squinting, cloudiness, or sudden changes always require veterinary evaluation.
Is dog eye discharge normal?
Small amounts of clear or brownish discharge in the inner corner of a dog’s eye are normal — these are simply dried secretions from the eye’s natural cleaning process. Reddish-brown tear staining in white or light-colored dogs is also common and usually benign. However, excessive tearing, mucus discharge, or any green or yellow discharge is not normal and should be evaluated by a veterinarian.
How do I clean my dog’s eye discharge?
Use a soft cloth or cotton ball dampened with warm water or sterile saline. Wipe gently from the inner corner outward, using a clean cloth for each eye. For stubborn tear staining, commercial tear stain removers are available. Never use human eye drops, contact lens solution, or hydrogen peroxide near your dog’s eyes. For long-haired breeds, keeping the periocular fur trimmed prevents hair from irritating the eye.
What does yellow or green eye discharge mean in dogs?
Yellow or green eye discharge indicates a bacterial infection and requires veterinary treatment. This type of discharge is never normal and often indicates conjunctivitis, a corneal ulcer, or a more serious eye infection. Your veterinarian will examine the eye, possibly stain it with fluorescein dye to check for corneal damage, and prescribe appropriate antibiotic eye drops. Don’t delay — untreated eye infections can lead to vision damage.
Why does my dog have brown discharge under their eyes?
Brown or reddish-brown staining under the eyes (epiphora) is caused by porphyrins — iron-containing compounds in tears that oxidize and stain the fur. It’s especially visible in white or light-colored breeds like Maltese, Bichon Frises, and Poodles. While usually cosmetic, sudden increases in tear staining can indicate a blocked tear duct, eye irritation, or allergies and warrant a vet check. Daily cleaning helps manage the appearance.
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