Dog Eye Discharge: Causes, When to Worry and What to Do

What it usually means

Eyes make tears all day to stay moist. The tears drain through small ducts at the inner corner of each eye into the nose and throat. Discharge is what remains or overflows: tears mixed with oil, mucus, dead cells and dust. A little clear or slightly reddish-brown crust, most noticeable in the morning, is normal as long as the amount stays about the same and your dog looks comfortable.

Color and texture help sort out what is going on.

• Clear and watery: irritation, allergies, a blocked duct, or an eye problem such as a scratch. Tears that overflow are called epiphora.
• Reddish-brown stains under the eyes: a pigment in tears darkens in the air, most visibly on light-colored dogs. Often only cosmetic.
• White-gray mucus: often dry eye, where the eye cannot make enough tears.
• Yellow or green: often an infection, which needs a vet.

Flat-faced dogs with prominent eyes are more prone to drainage trouble and to surface injuries. Allergies are another common reason for watery eyes.

Common causes

What you can do at home

For the normal morning crust, wipe gently with a clean, warm, damp cloth or a wipe made for dogs, moving away from the eye. Ask your groomer or vet to keep the hair around the eyes short, so it does not block drainage or poke the eye. Tear stains are easiest to manage by keeping the area clean and dry. No remedy works for every dog, and some over-the-counter products are unproven or can harm the eyes, so check with your vet first.

Before you wipe anything, look for red flags: squinting, pawing, redness, cloudiness or colored discharge. If you see any, skip home care and call your vet.

Never use leftover eye drops, human eye products or home remedies in a dog's eye. The right medicine depends on the cause, such as a foreign object, inflammation or an ulcer, and a vet has to work out which one. Avoid hydrogen peroxide products near the eyes too. If your dog keeps rubbing at the eye, ask the clinic whether a cone collar should be worn on the way in.

What happens at the vet

Your vet will ask when the discharge started, whether one eye or both is affected, what it looks like, and whether your dog could have scratched the eye or got something in it. The eye exam usually includes a few quick tests.

A drop of fluorescein dye makes scratches and ulcers on the cornea glow green. A Schirmer tear test measures how many tears the eye makes, which shows up dry eye. The dye can also show whether tears are draining toward the nose, and the vet may check pressure inside the eye if glaucoma is a worry.

Treatment depends on the cause. Infections and ulcers are usually treated with antibiotic eye drops or ointment, and dry eye with medication that helps the eye make or hold tears. A blocked tear duct can be flushed while your dog is under anesthesia. Eyelid problems and deep ulcers sometimes need surgery. Glaucoma is an emergency, because the pressure must come down quickly to protect sight.

Your vet may also send your dog home in a cone so rubbing does not damage the eye further while it heals. Superficial ulcers typically heal within about a week, while deeper ones take longer.

Prevention

Keep the hair around your dog's eyes trimmed short, and wipe away the morning crust before it builds up or irritates the skin. Check your dog's eyes regularly so you notice a change in the amount, color or consistency of discharge early.

If your dog has a flat face, prominent eyes or droopy eyelids, pay extra attention, since these dogs are more prone to surface injuries and tear drainage trouble. Treat squinting as a reason to call your vet, not something to watch for a week.

Get allergies managed with your vet if your dog's eyes water seasonally, and keep irritants such as dust and smoke away from the face when you can. If a cone has been prescribed after an eye injury, keep it on. Preventing rubbing matters, because further trauma can set healing back.

Finally, have any eye that stays red, runny or painful examined rather than treated at home. Some eye problems can lead to blindness if they are left alone, so early care is worth it.