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Dog Eye Discharge and Runny Nose: What Does It Mean?

By Patricia Williams
Last updated: September 17, 2026

When a dog has eye discharge and a runny nose, you may wonder whether the symptoms are connected or whether they reflect separate problems.

Mild, clear discharge may sometimes be temporary, but ongoing eye discharge and nasal drainage should be monitored closely, particularly if the discharge changes, becomes excessive, or is accompanied by other signs of illness.

We explain what eye discharge and a runny nose in a dog may indicate, what to watch for, and when veterinary assessment is needed.

Dog Eye Discharge and Runny Nose: Why It Happens

A dog may have eye discharge and a runny nose because of a respiratory infection, allergies, environmental irritation, or inflammation of the eyes and nasal passages.

Mild irritation can cause clear discharge from both the eyes and nose, while infections or other conditions may produce thicker mucus or discharge. Dental disease or a foreign object can also occasionally contribute to nasal discharge.

If the discharge is persistent, occurs mainly from one side, becomes bloody or thick, or is accompanied by coughing, fever, lethargy, or reduced appetite, veterinary evaluation is needed.

Dog Eye Discharge and Runny Nose: Common Causes

Upper Respiratory Infection

An upper respiratory infection is one of the more common explanations for eye discharge accompanied by nasal discharge.

Viral respiratory infections can cause inflammation of the nasal passages and may also produce watery eyes or conjunctivitis.

Dogs may sneeze, have a runny nose, develop eye discharge, or show other respiratory signs. Secondary bacterial involvement can sometimes make the discharge thicker or more mucus-like.

A dog with a mild respiratory infection may continue eating and behaving normally, particularly early in the illness.

Conjunctivitis

Conjunctivitis, or inflammation of the conjunctiva, can cause eye discharge, redness, swelling, and increased tearing.

When conjunctivitis occurs alongside nasal inflammation, the dog may also have a runny nose or sneezing.

Conjunctivitis can have infectious, allergic, irritant, traumatic, or other causes, so the presence of discharge does not automatically mean that a bacterial infection is responsible.

Nasal Irritation

Dust, smoke, aerosol sprays, fumes, and other airborne irritants can inflame the nasal passages and cause a runny nose.

The same exposure may irritate the eyes, resulting in watery discharge or excessive tearing.

If the symptoms began after exposure to a dusty environment, smoke, strong cleaning products, or another irritant, environmental irritation may be involved.

Allergies or Environmental Sensitivity

Environmental sensitivity can contribute to watery eyes and nasal discharge in some dogs.

Pollen, dust, mold, and other environmental substances may irritate the upper respiratory tract and eyes.

Allergic rhinitis is considered less common in dogs than some other causes of nasal inflammation, so persistent symptoms should not automatically be attributed to allergies.

Dogs with allergies may also have recurring skin itching, face rubbing, or symptoms that appear during particular environmental exposures.

Foreign Material in the Nose

A small piece of grass, plant material, dirt, or another foreign object lodged in the nasal passage can cause a sudden runny nose.

A foreign object becomes particularly important when the discharge is mainly coming from one nostril, especially if the dog is repeatedly sneezing, pawing at its face, or rubbing its nose.

Persistent one-sided nasal discharge should be evaluated rather than assumed to be a simple cold.

Foreign Material or Irritation of the Eye

Something irritating the eye can produce tearing and discharge while the same environmental exposure causes nasal irritation.

Dust, plant fragments, hairs, or other debris can cause increased tearing, blinking, squinting, or face rubbing.

If the dog is holding the eye closed or repeatedly rubbing it, the eye itself should be examined.

Tear-Duct Problems

The tear ducts provide a direct connection between the eyes and nose.

When a nasolacrimal duct becomes blocked or inflamed, tears may overflow from the eye instead of draining normally.

This can cause persistent wetness and discharge beneath the eye. Tear-sac inflammation can also produce watering eyes and conjunctivitis.

A tear-duct problem can therefore make it appear that a dog has an eye problem and a runny nose when the two signs are actually connected through the tear-drainage system.

Dental Disease

Disease involving the upper teeth can sometimes extend into nearby nasal or sinus structures.

An upper tooth-root abscess may contribute to inflammation in the adjacent nasal region and can be associated with nasal discharge.

Dental disease becomes more suspicious when the dog also has bad breath, difficulty chewing, facial swelling, or discomfort around the mouth.

Dry Eye

Dry eye, or keratoconjunctivitis sicca, occurs when the eyes do not produce enough tears.

Instead of normal watery tearing, affected dogs may develop persistent thick or mucus-like eye discharge along with redness and irritation. Corneal problems can develop if dry eye is left untreated.

Dry eye does not directly cause a runny nose, so when both signs occur together, the veterinarian may also look for nasal or respiratory disease occurring at the same time.

Nasal Mites

Canine nasal mites live within the nasal passages and sinuses and can cause sneezing, nasal discharge, facial itching, and sometimes nosebleeds.

They are not the most common explanation for eye discharge and a runny nose, but they may be considered when nasal symptoms are persistent or unusually intense.

Fungal Disease of the Nose and Sinuses

Fungal rhinitis can cause chronic inflammation within the nasal cavity and sinuses.

Dogs may develop persistent nasal discharge, sneezing, facial discomfort, and changes around the nose.

Some fungal diseases are more likely to produce long-lasting or progressively worsening nasal signs rather than a short episode that quickly resolves.

Nasal Growth or Tumor

A mass within the nasal cavity can cause chronic nasal discharge and other respiratory signs.

Nasal disease caused by a growth may begin with discharge from one nostril and later become bilateral.

A persistent discharge that changes character, becomes bloody, or is accompanied by facial changes is particularly important to investigate.

This possibility becomes more relevant when nasal and eye symptoms continue for a long period instead of behaving like a short-lived respiratory illness.

Dog Eye Discharge and Runny Nose but Acting Normal

A dog that is still eating, drinking, playing, and behaving normally may have a mild respiratory infection, environmental irritation, or uncomplicated eye inflammation.

However, acting normal does not identify the cause. Dogs can remain bright and active with several types of eye and nasal disease.

If the discharge continues, repeatedly returns, becomes thicker, or is accompanied by increasing sneezing or other symptoms, a veterinary examination can help determine whether the problem is limited to the eyes or involves the nasal passages as well.

Dog Eye Discharge and Runny Nose With Clear Discharge

Clear, watery discharge can occur with irritation, mild respiratory inflammation, increased tearing, or environmental sensitivity.

Clear discharge by itself does not establish that a condition is minor. The duration and other signs matter.

Persistent clear discharge from one nostril, for example, can have a different significance from temporary watery discharge from both nostrils during a short respiratory illness.

Dog Eye Discharge and Runny Nose With Yellow or Green Discharge

Yellow or green discharge generally reflects inflammation and the presence of cellular or inflammatory material, but the color alone does not prove that a bacterial infection is responsible.

Respiratory inflammation can cause nasal discharge to become mucus-like or mucopurulent, while conjunctivitis can also produce thicker eye discharge.

Persistent colored discharge, especially when accompanied by redness, squinting, lethargy, appetite loss, or worsening respiratory signs, should be evaluated.

Dog Eye Discharge and Runny Nose From One Side

When discharge is mainly coming from one eye or one nostril, a localized problem becomes more important to consider.

One-sided nasal discharge can occur with a foreign object, localized nasal disease, dental disease, or other structural problems.

Similarly, discharge from one eye can occur with a foreign object, tear-sac disease, dry eye, or another localized ocular problem.

A persistent one-sided pattern is therefore worth having checked, particularly if the dog is pawing at its face or the discharge contains blood.

When to Call or Visit the Vet

Have your dog evaluated if eye discharge and a runny nose persist, recur frequently, or progressively worsen.

Seek immediate veterinary attention if your dog has:

Difficulty breathing or labored breathing
An eye that is painful, cloudy, swollen, or held closed
Significant redness or swelling around the eye
Thick or persistent eye discharge
Bloody nasal discharge
Discharge consistently coming from only one nostril
Facial swelling or a change in the shape of the face
Repeated or forceful sneezing that does not settle
Intense face rubbing or pawing at the eye or nose

Loss of appetite or marked lethargy
Fever or significant weakness
Vision changes
Signs following facial trauma or possible foreign material
Nasal or eye discharge that continues for weeks or repeatedly returns

Breathing difficulty, severe eye pain, sudden vision changes, or rapidly worsening facial or eye swelling warrant prompt veterinary assessment.

Dog Eye Discharge and Runny Nose: Treatment

Treatment depends on whether the underlying problem involves the eyes, nasal passages, sinuses, tear ducts, teeth, or another part of the respiratory or ocular system.

The veterinarian may examine the eyes and nose, assess the conjunctiva and cornea, check tear production and drainage, and look for foreign material or other abnormalities.

Depending on the findings, testing may include eye tests, discharge samples, blood tests, dental evaluation, nasal imaging, CT, rhinoscopy, or biopsy for persistent nasal disease.

Treatment is directed at the underlying diagnosis rather than simply treating the appearance of the discharge.

Key Takeaway

Dog eye discharge and a runny nose can occur with respiratory infections, conjunctivitis, nasal irritation, allergies, foreign material, tear-duct problems, dental disease, nasal mites, fungal disease, or nasal growths. The combination alone does not identify the cause.

The pattern provides useful clues. Short-lived watery discharge may occur with irritation or a mild respiratory problem, while persistent, thick, bloody, or one-sided discharge deserves closer investigation.

Eye pain, facial swelling, breathing changes, or vision problems are especially important warning signs.

If your dog’s eye discharge and runny nose persist, worsen, or keep returning, a veterinarian can determine whether the problem is primarily ocular, nasal, respiratory, dental, or related to another underlying condition.