Discharge From a Dog’s Eyes

Medically Reviewed by Amy Flowers, DVM on January 31, 2023
6 min read

Eye discharge is a common problem for some dogs. It can be a sign of anything from infection to glaucoma to allergies.

If your dog has clear eye discharge, chances are good it's caused by allergies or something physical, like dust in the eye or wind blowing in the face. A watery discharge or mucus from one eye is often a sign of a foreign body, like an eyelash, while yellow-green or pus-like eye discharge could indicate a serious infection. Because eye problems can be a sign of brain or nerve injury, infection, or other serious problems, have your dog's eyes checked by a veterinarian to find out what's behind your dog's eye discharge.

Conjunctivitis is also known as pinkeye or red eye, and it’s as common in dogs as it is in humans. Mucus, yellow-green pus, or a watery eye discharge can all be signs of conjunctivitis, an inflammation of the lining of your dog's eye. There's a wide range of causes for conjunctivitis, from allergies, injury, birth defects, and tear duct problems to foreign matter, dry eye, distemper, or even tumors. Here are some symptoms you can look for: 

Dog conjunctivitis symptoms

  • Redness
  • Puffy eyelids
  • Stringy discharge
  • Watery eyes
  • Pawing at their eyes
  • Squinting
  • Eyelids that stick together

At the first sign of these symptoms, it’s best to take your dog to the vet. They can tell what type of conjunctivitis you’re dealing with and how to treat it. Plus, your dog may have a more serious condition that could cause blindness if left untreated. It’s important that you don’t try to treat an undiagnosed eye condition yourself, as medication for one condition may aggravate another.

To treat conjunctivitis, it's important to learn what's causing it. Depending on the cause, treatment can include removing the irritant and soothing the area with pain medication, antibiotics and saline washes to manage infection, surgery to treat duct problems or birth defects, antihistamines for allergies, or other medications.

Common types of dog conjunctivitis

Allergic conjunctivitis

This allergic reaction is often seasonal and not contagious.

Causes include:

  • Dust mites
  • Pollen
  • Mold
  • Dander
  • Cosmetics and perfumes
  • Drugs

Treatments for allergic conjunctivitis include

  • Cold compresses
  • Artificial tears
  • Nonsteroidal anti-inflammatory drugs
  • Antihistamines
  • Steroid eye drops

Viral conjunctivitis

This is caused by a virus, spreads easily, and can take up to 3 weeks to get better.

Viral conjunctivitis symptoms include:

  • Cold-like symptoms
  • Upper respiratory infection

Viral conjunctivitis treatments include:

  • Cold compresses
  • Artificial tears
  • Steroid eye drops

Bacterial conjunctivitis

This type is also very contagious.

Causes include:

  • Streptococcus (strep)
  • Staphylococcus (staph infection)

Bacterial conjunctivitis treatments include antibiotic eye drops or ointments.

These can be superficial or deep sores that can be painful. They may be caused by trauma to the cornea, disease, a lack of tears, something foreign in the eye and other injuries. Corneal ulcers cause red and watery eyes, sensitivity to light, squinting, rubbing the eyes with a paw, or rubbing on furniture/floor, a film over the eye, and discharge from the eye. Treatment may require antibiotics, corneal repair drops, anti-inflammatories, or surgery. Take your dog to the vet right away.

Watery, teary eyes -- resulting in stained or smelly fur or infected skin -- can also be the result of many conditions, including abnormal eyelashes, inflammation, allergies, corneal ulcers, tumors, eye pain, and more.

Treating excessive tearing depends on what's causing it. Treatments include topical antibiotics or steroids for tear duct inflammation,  antibiotics and topical medication for cornea damage, or surgery for duct obstruction, ulcers, or abnormal eyelashes. 

A sticky, tenacious eye discharge could point to canine dry eye, a failure to make enough tears. Symptoms can also include mucus and inflammation. Dry eye may be the result of distemper, injury, a knock in the head near a tear-producing gland, or the dog's immune system attacking the tear gland tissue. Infection is a serious risk for dogs with dry eye and can lead to painful, inflamed eyes. Ulcers on the cornea (surface of the eye) are also a serious risk since, without the lubricating effect of tears, the eyelid can scratch the surface of the eye just by opening and closing.

Treatment for dry eye depends on how severe it is and includes artificial tears for several weeks for mild dry eye, antibiotic eye drops to help manage secondary infections, immunosuppressant drugs to help control the immune system, or surgery.

This condition is caused by excessive pressure in the eye and can be spotted in a few ways, including a bulging eye or eyes, cloudy eyes, and sometimes tearing. Glaucoma causes a lot of pain; the vet may try to manage the ocular pressure with medications, but surgery may be recommended. 

Flat-faced dogs like pugs, Pekingese, boxers, and bulldogs can be more prone to eye discharge than other breeds because their flatter faces often mean shallower eye sockets and protruding eyes.

Called brachycephalic breeds, dogs with more prominent eyes may have tear drainage problems; eyelids that roll inward (entropion), causing great irritation by the lashes; or lids that don't close fully over their eyes, a condition that can require surgery.

Breeds with loose facial skin, like bloodhounds, cocker spaniels, beagles, Saint Bernards, and some terriers, are more prone to eyelids that roll outward (ectropion), as well as cherry eye, a condition that occurs when a gland in the eyelid falls out of position. While antibiotics and steroids can help, surgery is often necessary for these conditions.

Treatment for eye problems sometimes requires eye drops or ointments. To make them easier to administer, try these tips:

  • Have the eye drops or ointment close at hand, then clean away any discharge around your dog's eyes with warm water and a cotton ball.
  • For eye drops, tilt your dog's head back a little. Then, resting your hand on your dog's head so you don't hit its eye with the dropper if the dog moves, squeeze drops into the upper part of your dog's eye.
  • To apply eye ointment, gently pull down your dog's lower lid, creating a pocket for the ointment. Rest your hand on your dog's head. That way, if the dog moves, you won't hit the eye with the ointment applicator. Then squeeze a ribbon of ointment into the dog's eye.
  • Gently open and close the lids for a few seconds to help spread the ointment or drops evenly.

First, take a good look at your dog's eyes. The pupils should be the same size and your dog's eyes should be bright, crust-free, with white around the iris. There should be little or no tearing, no squinting, and the inner eyelids shouldn't be visible. Gently pull down your dog's lower lids: they should be pink, not red or white.

If you see tearing, discharge, tear-stained fur, cloudiness, a third eyelid, closed or squinted eyes, or pupils of unequal size, something could be wrong. It's time to give your vet a call.

To help keep your canine companion's eyes bright and healthy, keep long hair out of its eyes (take your dog to a groomer or use round-tipped scissors to trim the hair); keep irritants like shampoos, soaps, and flea medicine away from the eyes; and, finally, watch for signs that may indicate an eye problem, like redness, pawing, rubbing, and squinting.