Eye discharge combines tear film (water, mucus, and oil) with dead skin cells, organic debris, and dirt. Discharge collects in the corners of the eyes, forming boogers or crusts. 

The discharge has a protective function and is standard in limited amounts. Excess discharge indicates an underlying eye condition. 

The most common cause of discharge is a dog eye infection. Other causes include airborne irritants and allergens, dry eyes, ulcers and abrasions, foreign bodies, glaucoma, eye tumors, and eyelid abnormalities (cherry eye, entropion, and lumps). 

Regular cleaning of the eyes helps remove dog eye boogers. Topical and systemic medications or surgery provide definitive treatment. 

Eye hygiene, regular veterinary checkups, and eye supplements reduce the risk of conditions that cause watery, yellow, or green discharge from dog eye.

What is Eye Discharge in Dogs?

Eye discharge in dogs is a mix of tears, mucus, oil, shed skin cells, and debris that collects in the corners of the eye.

The dog’s eye naturally produces a so-called tear film, which has three components, water, mucus, and oil. The protective tear film flushes the eyes to cover the corneal surface. 

The water component evaporates faster than mucus and oil. The remaining oil and mucus have a thicker consistency and form eye discharge or boogers when mixed with skin cells and dirt.  

Dog eye discharge is oily, moist, or crunchy, depending on how much water evaporates from the eye surface.

A small amount of clear or ivory-colored eye discharge in dogs is normal, especially after waking up. Excess discharge suggests an underlying eye condition, such as a dog eye infection. 

Do the Dog Eye Boogers Indicate Health Condition?

No, dog eye boogers do not indicate health conditions. Eye boogers form when dried tears mix with dead skin cells, oil, mucus, dust, and dirt. 

The standard eye booger is transparent with a slightly reddish-brown-green color. Eye boogers are expected and occur most often in the morning and after the dog awakes from a nap. 

Dogs produce similar amounts of eye boogers every night, and owners know how much goop is normal. 

Excess boogers are abnormal and indicate eye infections in dogs. Prompt veterinary attention and dog eye infection treatment are necessary to stop the problem. 

Does the Eye Discharge Mean a Dog Eye Infection?

Yes, eye discharge means a dog eye infection in many cases. Eye infections are among the most common causes of eye discharge. 

Eye infections are primary when developing on their own or secondary when triggered by other eye problems. Redness, swelling, and epiphora (increased tearing) are telltale signs of ocular infections in dogs.  

Infections are one of several eye conditions that cause discharge. Entropion, keratoconjunctivitis sicca (KCS), and corneal ulcers are common eye problems in dogs that manifest with discharge. 

What Does Green Discharge from Dog Eye Mean?

Green discharge from dog eye means a serious infection. Green discharge in dogs indicates bacterial conjunctivitis (inflammation of the conjunctiva) or keratitis (inflammation of the cornea). 

The green discharge is loose and sporadic or thick and sticky, depending on the severity of the infection. The thick discharge version has an unpleasant smell in most cases. 

Eye infections causing green discharge manifest with pronounced eye redness, swollen eyelids, increased tearing, and photophobia (light sensitivity). Dried discharge and crusts on the corners of the eyes and eyelids are possible. 

What Does Yellow Eye Discharge Dog Mean?

Yellow eye discharge dog means meibomian gland problem or bacterial eye infection. 

Crusty yellow flakes at the base of the eyelashes and yellow mucus-like discharge occur in dogs with meibomian gland obstruction. 

The meibomian glands, which produce the oily component of the dog’s tear film, are lined along the eyelid margin. Clogging of the glands causes eyelid lumps and yellow discharge. 

The presence of thick and sticky yellow discharge indicates contagious bacterial conjunctivitis. The discharge turns from yellow to green as the infection progresses. 

What are the Causes of Eye Discharge in Dogs?

The causes of eye discharge in dogs are listed below. 

• Airborne Irritants: Irritants in the air cause watery discharge in sensitive dogs. Common airborne irritants include cigarette smoke, perfumes, scented air purifiers or candles, aerosolized cleaning products, and engine combustion gasses.
• Allergens in the Air: Airborne allergens cause allergic conjunctivitis accompanied by watery discharge. Grass and flower pollen, dust, human and pet dander, feathers, mold spores, and mildew are widespread culprits for allergic conjunctivitis. 
• Eye Infections: Bacterial and viral infections are among dogs' most common causes of greenish-yellow eye discharge. Fungi and parasites trigger eye infections but are less frequently seen. 
• Dry Eye: Dry eye, or keratoconjunctivitis sicca, is a chronic inflammation of the cornea and conjunctiva triggered by reduced tear production or tear quality. The water part of the tear film is lacking, and the discharge is moist and sticky.  
• Corneal Abrasions: Corneal abrasions are minor cuts or grazes on the surface of the dog’s eye caused by trauma (sharp grass blades or other pets’ nails). Corneal abrasions cause watery discharge, which turns into sticky, yellow, or green if an infection occurs. 
• Corneal Ulcers: Corneal ulcers are open sores or defects on the eye. Ulcers are deep and associated with injuries, dry eye, untreated infections, and systemic illness. Ulcers are painful and trigger watery to hazy discharge. 
• Glaucoma: Glaucoma is an increased intraocular pressure (IOP) caused by primary or secondary triggers. Glaucoma provokes more profuse tearing, eventually creating a clear, transparent eye discharge. 
• Injuries and Foreign Bodies: Dog injuries occur during playtime and while sniffing on the ground. Sniffing allows foreign bodies, like grass awns and foxtails, to pierce the eye's surface, causing red or bloody discharge. 
• Ocular Tumors: Tumors growing inside or near the eye cause pressure, increasing tear production and eye discharge. The frequently reported type of eye cancer in dogs is uveomelanoma, a melanoma that grows from the uveal tissues. 
• Entropion: Entropion is a hereditary abnormality in which the eyelid curls inward. The eyelashes cause increased tearing and eye discharge in dogs with entropion, irritating the cornea. Bulldogs, Mastiffs, and Rottweilers are predisposed to entropion. 
• Cherry Eye: Cherry eye is a prolapse of the third eyelid gland (nictitans gland) located inside the third eyelid (known as the nictitating membrane). The prolapsed gland resembles a cherry in the corner of the eye and causes irritation and watery eye discharge. 
• Eyelid Lumps: Common eyelid lumps include chalazia (clogged meibomian glands) and tumors, such as meibomian gland adenoma, adenocarcinoma, melanoma, and papilloma. Eyelid lumps irritate the eye and trigger discharge. 

Why Does My Dog Have Eye Boogers All of A Sudden? 

Your dog has eye boogers all of a sudden because it suffers from eye discharge. Boogers form when eye discharge dries up due to air exposure.  

The two most common causes of excess eye boogers in dogs are eye infections and seasonal allergic conjunctivitis. 

Eye infections cause a yellow to green discharge that forms crusty eye boogers. The boogers associated with allergies are more transparent and less sticky.  

How can Eye Discharges Affect Dogs?

Eye discharge can affect dogs in the ways listed below. 

• Pain or Discomfort: Eye conditions causing discharge are painful or uncomfortable. For example, glaucoma is unbearable, while allergic conjunctivitis causes an uncomfortable itch. 
• Light Sensitivity: Light sensitivity or photophobia is a common accompanying sign of eye discharge in dogs. Squinting and blinking are typical for dogs with light sensitivity. 
• Blurry Vision: Eye discharge, boogers, and crusts harm the dog’s vision. 
• Eye Injuries: Some causes of eye discharge in dogs trigger itchiness. The dog paws at its eyes and scratches them to soothe them, resulting in injuries. 
• Behavioral Changes: The pain, discomfort, light sensitivity, blurry vision, and itchiness result in altered behavior, including moodiness and irritability. 

Can Glaucoma Cause Eye Discharge in Dogs?

Yes, glaucoma can cause eye discharge in dogs. Glaucoma is a severe condition caused by increased intraocular pressure (IOP) or pressure within the eye. 

Glaucoma is progressive and potentially blinding. Increased tearing and eye discharge are signs of glaucoma but are not exclusive to the condition. 

Certain dog breeds, such as American Cocker Spaniels, Basset Hounds, Boston Terriers, and Wire Fox Terriers, are predisposed to glaucoma eye disease.  

Does Eye Discharge Cause Dogs Eyes Watering?

No, eye discharge does not cause dogs eye watering. Eye-watering leads to eye discharge. Eye discharge in dogs is comprised of dried tears mixed with other components. 

Allergen exposure, hot and dry air, and airborne irritants like cigarette smoke, scented candles, perfumes, and aerosolized cleaning products are common watering causes. The medical term for dog eye watering is epiphora. 

What are Treatments for Dog Eye Discharge?

The treatments for dog eye discharge are listed below. 

• Tear Stimulants and Artificial Tears: Tear stimulants (lacrostimulants) or replacements like artificial tears are recommended for dogs with dry eyes or keratoconjunctivitis sicca. These medications are available as drops or ointments and must be used several times daily. 
• Antibiotic and Anti-inflammatory Topicals: Drops and ointments with antibiotic and anti-inflammatory active ingredients are prescribed for dogs with eye infections or when there is a high risk of infection. Corneal ulcers benefit from local antibiotic meds. 
• Anti-Glaucoma Drops: Anti-Glaucoma drops contain ingredients that lower the dog’s intraocular pressure. Anti-glaucoma drops are given once or several times a day based on how regulated the pressure inside the eye is. 
• Systemic Antimicrobials: Antimicrobials include oral medications such as antibiotics, antivirals, antifungals, and antiparasitics. Systemic antimicrobials are given to dogs with primary and secondary eye infections. 
• Eye Surgery: Eye surgery is reserved for severe discharge causes, including glaucoma and cataracts that fail to respond to medical treatment. Eye tumors, injuries, and foreign objects require surgical treatment. 
• Surgical Eyelid Correction: Surgical eyelid correction treats dogs with cherry eye, entropion, and some eyelid lumps. V-plasty and blepharoplasty are possible options for lumps, depending on their size. 
• Other Treatment Options: Secondary dog eye discharge treatments include reducing allergen exposure. Cryotherapy and laser ablation are minimally invasive alternatives to surgery for dogs with eyelid tumors.

When Can You Say that Your Dog's Eye Booger Is Normal?

You can say that your dog’s eye booger is normal if it is easy to clean with a damp cloth, the eye is not red, and the dog is not showing any signs of discomfort. 

The main characteristics of the booger indicate its nature. For example, normal boogers are clear or ivory-colored with a pale brown, red, or green shade. Boogers are not smelly and not overly sticky.  

Boogers are standard in the morning and immediately after the dog’s nap. Dog eye boogers are expected after open-window car rides, in which the dog keeps its head out of the vehicle. The blowing air dries the eye and deposits. 

Can Eye Discharge in Dogs Go Away without Treatments?

Yes, eye discharge in dogs can go away without treatment. For example, watery discharge in dogs, caused by reflex tearing, resolves alone. 

Reflex tearing occurs when the dog’s tear glands produce excess water to flush out a potential irritant or to provide comfort when dry, hot air dehydrates the eye's surface. 

The excess watery discharge produced during reflex tearing disappears once it has completed its purpose. 

Yellow-green, sticky, and smelly eye discharge does not resolve without treatment because it is a symptom of a more severe underlying eye problem. 

Can Eye Discharge in Dogs Be Prevented?

Yes, eye discharge in dogs can be prevented. Maintaining eye health through hygiene, veterinary checkups, and eye supplements is the cornerstone of preventing eye discharge. 

Clean the dog’s eyes and boogers using pet-specific eye washes or wet wipes and maintain the fur around the eyes well-trimmed. 

Practice annual or biannual vet checkups to ensure optimal health and catch issues before they advance. 

Eye supplements are commercially available and include formulas rich in beta-carotene, antioxidants, and healthy fatty acids.  

Ensure the dog is current on vaccines to prevent infections and reduce exposure to airborne allergens and irritants in sensitive dogs. 

Can Allergies Cause Eye Discharges?

Yes, allergies can cause eye discharge in dogs. Increased tearing is a common sign of allergic conjunctivitis. 

Allergic conjunctivitis is inflammation of the conjunctiva caused by airborne allergens. Airborne allergens include pollen (from grass, trees, or flowers), pet dander, human dander, feathers, dust, mites, mold spores, and mildew.  

Periocular and ocular allergy signs are present in 60% of dogs with canine atopic dermatitis, according to a study, “Allergic Conjunctivitis and Conjunctival Provocation Tests in Atopic Dogs,” published in Veterinary Ophthalmology in 2011.  

The eye discharge caused by allergies is clear and watery. The main effect is to flush allergens and prevent irritating allergic reactions in dogs.