Introduction
A dog’s eyes are delicate and sensitive, so it can be alarming when you notice redness, swelling, or discharge. There are many potential causes for a dog’s eye to appear red and goopy. It’s important to identify the cause in order to get proper treatment.
Some common reasons a dog’s eye may become red and have discharge include:
- Conjunctivitis (inflammation of the conjunctiva)
- Allergies
- Foreign objects lodged in the eye
- Eye infections
- Dry eye
- Glaucoma
- Cherry eye
- Eye tumors
In this article, we’ll explore these common causes in more detail. We’ll also discuss when it’s necessary to see the veterinarian regarding your dog’s red, goopy eye.
Conjunctivitis
Conjunctivitis, also known as pink eye, is inflammation of the conjunctiva, which is the thin, transparent tissue that lines the inner surface of the eyelid and covers the white part of the eye.
The symptoms of conjunctivitis include:
- Redness in one or both eyes
- Thick yellow or greenish discharge from the eyes
- Crusting of discharge on the eyelashes, especially after sleep
- Feeling like something is in the eye or an irritated, gritty feeling
- Itching or burning sensation in the eye
- Watery eyes
Conjunctivitis can be caused by:
- Allergies to pollen, dander, smoke, or other irritants
- Bacterial or viral infections
- Chemical or physical irritants such as makeup, perfumes, chlorinated water
- Foreign objects like dust or sand irritating the eye
Allergies
Allergies are a common cause of red, goopy eyes in dogs. Allergic reactions can be triggered by pollen, dust mites, certain foods, and other environmental allergens. When dogs are exposed to an allergen, it can cause an allergic reaction in the eyes known as allergic conjunctivitis.
The main symptoms of allergic conjunctivitis include:
- Redness in the whites of the eyes
- Itchy eyes
- Watery discharge
- Goopy mucus secretion
To treat allergic conjunctivitis, vets may prescribe antihistamine eye drops to stop the allergic reaction and reduce swelling. Restricting exposure to the allergen can also help, whether it’s keeping your dog indoors during peak pollen times or switching to a hypoallergenic dog food.
Foreign Objects
Dust, dirt, and eyelashes can sometimes get stuck in your dog’s eye and cause irritation. When this happens, your dog’s eye will likely appear red, watery, and may have some discharge or goop coming from it as the eye tries to wash out the foreign object.
Some signs that there is something stuck in your dog’s eye include:
- Redness in one eye
- Excessive blinking or squinting
- Pawing at the eye
- Green, yellow, or white discharge coming from the eye
If you notice any of these signs, try flushing your dog’s eye with an eyewash solution. This can help dislodge dust, dirt, or eyelashes stuck on the surface of the eye. Just make sure to use a sterile saline solution and avoid getting any in the non-affected eye. If the irritation persists more than a day or two, it’s best to have your vet take a look to make sure there is nothing embedded in the eye that requires further treatment.
Infection
Common infections causing red, goopy eyes in dogs include bacterial, viral and fungal infections.
Some types of bacterial infections include Staphylococci, Streptococci, Pseudomonas and Proteus. These bacteria can cause conjunctivitis and keratitis, which are inflammation of the conjunctiva and cornea, respectively. Signs include redness, discharge and eye pain. These bacterial infections are highly contagious between dogs and often require antibiotic eye drops or ointment to treat.
Viral infections like canine herpesvirus and canine adenovirus are less common but can spread quickly between dogs. They usually cause inflammation, ulceration and discharge from the eye. Antiviral medication may help, but most viral eye infections need to run their course.
Fungal infections are rare but Aspergillus, Cryptococcus and Blastomyces fungi can infect the eye. They often occur secondary to a weakened immune system. Anti-fungal eye medications are needed for treatment.
In most cases of bacterial, viral or fungal eye infections in dogs, antibiotics or other medications are necessary for treatment and control of the infection. Seeking prompt veterinary care is advisable.
Dry Eye
One potential cause of a red and goopy eye in dogs is dry eye (keratoconjunctivitis sicca). Dry eye occurs when the tear glands in your dog’s eyes do not produce enough tears to keep the eyes properly lubricated.
Without sufficient tear production, your dog’s eyes can become irritated and inflamed. The lack of tears causes the eyes to become red and the increased irritation leads to discharge and goopiness. Over time, persistent dry eye can cause damage to the cornea and impair vision if left untreated.
Some common signs of dry eye in dogs besides redness and discharge include excessive blinking, squinting, pawing at the eyes, cloudiness of the corneas, and ulcers on the corneas. Dry eye is most common in middle aged and older dogs, as well as brachycephalic breeds like Pugs and Bulldogs.
If your dog is showing any of these symptoms, it’s a good idea to take them to the vet to be evaluated for dry eye. It can be diagnosed through a Schirmer tear test. Dry eye is typically treated with prescription eye drops to increase tear production and lubricate the eyes.
Glaucoma
Glaucoma is a condition caused by increased pressure in the eye. It occurs when fluid builds up in the front part of the eye and cannot drain properly. This increased pressure can damage the optic nerve over time, leading to vision loss and blindness if left untreated.
One of the most common symptoms of glaucoma is redness in the eye. The increased pressure irritates the blood vessels on the surface of the eye, causing them to become swollen and red. You may also notice your dog’s eye looks hazy or cloudy, and the normally clear cornea starts to take on a blueish tint.
Along with redness, dogs with glaucoma often have increased tear production and ocular discharge. You may see yellow or greenish goop coming from the eye as it waters excessively. The eye may be held partially closed, since the pressure causes discomfort and pain.
As glaucoma worsens, you’ll notice vision loss or changes in your dog’s behavior. They may start bumping into objects or seem confused navigating around the house. The pupils may also become dilated and non-reactive to light due to the optic nerve damage.
Glaucoma is an emergency requiring immediate veterinary care. Pressure-reducing eye medications are needed to try to prevent permanent damage and blindness. Sometimes surgery is recommended to help fluid drain properly. Catching and treating glaucoma early is key to preserving vision.
Cherry Eye
Cherry eye refers to a prolapse of the third eyelid gland in dogs. This gland is located in the third eyelid, in the inner corners of the eye.
With cherry eye, this gland prolapses and protrudes out as a red, rubbery mass that looks like a cherry in the corner of the eye. The protruding gland may appear swollen and irritated.
Cherry eye usually develops in younger dogs under the age of 2 years old. Brachycephalic breeds like Bulldogs, Boston Terriers, and Pekingese are more prone to this condition.
The exact cause is unknown but may be due to a weakness in the connective tissue that allows the gland to protrude. Trauma, inflammation, or allergies may also contribute to cherry eye.
Cherry eye does not usually cause discomfort but the exposed gland is prone to irritation. Leaving cherry eye untreated can lead to secondary infections or dry eye.
Cherry eye requires veterinary treatment. Options include medicated ointments, gland replacement, or surgical tacking to tack the gland back into place. Surgery provides the best long-term solution.
Tumors
Growths in or around the eye, whether cancerous or benign, can cause irritation and other symptoms in dogs. Eye tumors may appear on the eyelid, third eyelid, conjunctiva, cornea, or other structures surrounding the eyeball.
Some common types of eyelid tumors in dogs include:
- Sebaceous adenomas – benign tumors of the oil glands, often appearing as round bumps on the eyelid margins
- Meibomian gland adenomas – benign growths of the meibomian glands on the eyelids
- Melanomas – malignant pigmented tumors
- Histiocytomas – benign masses that may regress spontaneously
Growths inside the eye such as melanocytic tumors of the iris are less common but can obstruct vision and be locally invasive if malignant. Optic nerve sheath meningiomas are slow-growing tumors that can compress the optic nerve.
While most eyelid tumors in dogs are benign, any abnormal growth should be evaluated by a veterinarian. Biopsy and imaging tests may be recommended to determine if a tumor is cancerous and if/how it should be treated or monitored.
When to See a Vet
If your dog’s eye is red, swollen, or oozing, it’s important to have a veterinarian examine it as soon as possible. Some signs that warrant an urgent vet visit include:
- Sudden onset of redness, swelling, or discharge from the eye
- Squinting, pawing at the eye, or rubbing the eye on furniture
- Cloudy appearance in the cornea
- Visible foreign object stuck in the eye
- Eye injury from trauma
- Crusty, encrusted eyes in the morning
- Vision loss or changes in the appearance of the pupil
Getting prompt veterinary attention is crucial, as some eye conditions can progress quickly and cause permanent damage if left untreated. Your vet will perform a thorough eye exam to determine the underlying cause and recommend appropriate treatment, which may include:
- Eye drops or ointments
- Oral medications
- Removal of foreign objects
- Surgery in severe cases
Don’t hesitate to call your vet if your dog is showing signs of eye redness, irritation, or vision issues. Acting quickly can help relieve discomfort and prevent long-term problems.