Red Eyes and Eye Discharge in Dogs: When to Worry

A little dried crust in the corner of the eyes in the morning is normal for many dogs. But red eyes, lots of tears, thick yellow-green discharge or constant squinting are another matter. The eye is delicate, and some conditions can cost a dog its sight within days, so don't wait too long.

Normal discharge versus worrying discharge

• Normal: a small amount of clear or light brown discharge that dries in the eye corners after sleep, wipes off easily, with no redness or discomfort.
• Reddish-brown tear stains: common in white-coated and flat-faced dogs. Usually from tears overflowing; the cause should be checked, but it's rarely urgent.
• Worrying: thick, yellow or green discharge in large amounts that sticks the lids together; red, swollen eyes; squinting, rubbing the eyes or sensitivity to light.

Each type of dog has its own weak spots. Flat-faced dogs with prominent eyes scratch their corneas easily; long-haired dogs get hair poking their eyes; older dogs are prone to dry eye and clouding. Knowing which group your dog belongs to helps you notice problems sooner.

Common causes

• Irritation from dust, wind, smoke or shampoo: mild redness and watering, usually better after rinsing.
• Allergies: red eyes with clear, watery discharge and itching, often with face scratching, paw licking or ear infections.
• Conjunctivitis: the pink tissue around the eye becomes red and swollen with discharge. Caused by bacteria, viruses, allergies or irritants.
• Dry eye: the tear glands produce too few tears, leading to thick, sticky discharge and a dull, hazy cornea. Common in some small breeds and easily mistaken for ordinary conjunctivitis.
• Corneal scratches or ulcers: from scratching, branches, ingrown eyelashes or foreign bodies. The dog is in pain, squints and tears heavily. Flat-faced dogs with prominent eyes are very prone.
• Eyelid and eyelash problems: eyelids that roll inward or lashes that rub on the eye cause ongoing irritation.
• Prolapsed third eyelid gland: a pink-red lump bulging from the inner corner of the eye, common in young dogs.
• Glaucoma or uveitis: a red, painful eye, an abnormal pupil and a cloudy blue cornea. This is an emergency.
• Whole-body illness: distemper in unvaccinated dogs can start with eye discharge and a runny nose; some tick-borne diseases also cause eye inflammation.

Safe eye care at home

The steps below are basic care only and don't replace a vet visit when something looks wrong:

1. Wipe discharge gently: use clean cotton or gauze moistened with sterile saline, wiping from the inner corner outward. Use a separate piece for each eye.
2. Trim hair around the eyes: for long-haired dogs, keep hair from poking the eyes. If you're not confident, ask an experienced groomer, using round-tipped scissors.
3. Avoid irritants: shield the eyes during baths and keep shampoo out of them. Don't let your dog hang its head out of the car window.
4. Stop eye rubbing: if your dog keeps pawing at its eye, a protective cone may be needed until it's examined.

What not to do

• Don't use human eye drops or leftover eye medicine. Some eye drops contain ingredients that make a corneal ulcer worse.
• Don't apply leaves, tea, milk or other home remedies to your dog's eyes.
• Use any eye drops or ointments only as directed by your veterinarian, and read the product label carefully.

When to see a vet

Eye problems progress fast. See a vet the same day if you notice:

• Squinting, keeping one eye closed, constant rubbing or sensitivity to light.
• A cloudy, bluish cornea, a white spot or a dent on the surface.
• An eye bulging more than usual, or an eye that has been hit or scratched.
• Heavy, thick yellow-green discharge with a red, swollen eye.
• Pupils of different sizes, bumping into things, or apparently poor vision.
• Eye discharge with fever, coughing, runny nose or loss of appetite, especially in a dog not fully vaccinated.
• A red lump bulging from the corner of the eye.
• Mild redness and watering that doesn't improve after a day or two of gentle cleaning.