Both humans and dogs may experience various eye conditions throughout their lifetime, whether it be an injury, infection or a more serious issue. One such condition both beings can contract is conjunctivitis, better known as pink eye. 

Pink eye in dogs can be triggered by one or a number of factors, including allergies, parasites, bacterial or viral infections. Although some cases of canine pink eye are milder than others, it is important to schedule a visit with your veterinarian as soon as possible to get the proper treatment for your furry friend.

Canine conjunctivitis occurs when a dog’s conjunctiva (the thin pink mucus membrane that covers the inner surface of the eyelids and part of the front surface of the eye) becomes inflamed. The condition can be identified by red, swollen eyes, and is accompanied by discharge in many cases.

Unlike humans, dogs have a third eyelid called a “nictitating membrane” that the conjunctiva also covers. This is located in the lower portion of the eye nearest the nose. When a dog contracts conjunctivitis, each of the eyelids can be affected.

Several things can cause pink eye in your dog. These include conditions and circumstances such as:

• Eye allergies to pollen, mold, dust, smoke or cosmetics
• Parasites, including eye worm
• Bacterial infections
• Viral infections, including canine distemper and canine herpes
• Injury or trauma
• Dry eye (keratoconjunctivitis sicca (KCS))
• Insect or animal bites
• Dirt, grass or other foreign objects entering the eye
• Tumors
• Eyelid disorders such as entropion and ectropion
• Blocked or obstructed nasolacrimal (tear) ducts
• Canine glaucoma and other eye diseases

Some dogs are more susceptible to conjunctivitis and other eye infections due to conditions associated with the breed. For example, many collies develop nodular episcleritis, a disease in which the sclera of the eye becomes inflamed and a small growth develops.

Symptoms of conjunctivitis in dogs can be mild or severe, and it’s important to monitor symptoms of any kind and report them to your vet. Some to look out for include:

• Redness

• Swelling

• Discharge (may be clear, yellow, green or even bloody)

• Excessive blinking or squinting

• Pawing or rubbing the affected area

Either one or both eyes can be affected by conjunctivitis — sometimes it starts in one eye and spreads to the other, and some cases begin in both eyes at the same time. Your dog may also experience sneezing or coughing with the condition.

These symptoms can also be indicative of other eye conditions in your dog, but your veterinarian will be able to provide a clear diagnosis (whether or not it’s conjunctivitis) based on the root cause, symptoms and appearance during an exam.

Conjunctivitis is diagnosed through a physical eye examination performed by your veterinarian. Your dog will receive a comprehensive eye exam, during which the following may be performed:

• A physical exam of the inner and outer eye structures, including the lashes, lids and tear ducts
• Corneal staining tests, which help determine if the cornea is damaged
• A tear production test
• An intraocular pressure test to determine if glaucoma is present

Your vet may suggest other tests depending on the condition. Once a formal diagnosis has been made, treatment can begin.

Proper treatment for conjunctivitis in dogs depends on what caused the condition to develop in the first place. If conjunctivitis occurred because of a specific disease or underlying eye condition, the primary treatment will likely be for that condition.

The options for conjunctivitis treatment range from artificial tears to surgery, and can come in forms of topical and/or oral medication. In addition to specific veterinarian-recommended treatments, cool or warm compresses may also help relieve pain or irritation — regardless of the cause of conjunctivitis.

Artificial tears

Flushing the eyes with a saline rinse or artificial tears may be recommended for conjunctivitis caused by the following:

• Dry eyes (non-KCS)
• Mild allergies
• Viral infections 

Artificial tears can also help wash away dirt from the eyes to relieve some pain and prevent further damage. Additionally, artificial tears can be used in combination with other treatments to soothe the irritation in the eyes.

Steroids, antihistamines and anti-inflammatories

Temporary relief and treatment can be found in oral and topical steroids, antihistamines and anti-inflammatories. Conditions like the following can benefit from these types of medication:

• Severe allergies
• Infections

Immunosuppressants 

Immunosuppressants such as cyclosporine and tacrolimus ophthalmic are often prescribed for dogs that have KCS in order to promote proper tear production. This helps prevent complications (such as conjunctivitis) from occurring.

Antibiotics

Many times, specific antibiotics are prescribed to help a pet’s condition. Antibiotics may help with the following:

• Bacterial infections
• Skin infections that develop alongside conjunctivitis

Depending on the treatment needed, antibiotics are either taken topically or orally. Your vet will give you instructions for administering either type of antibiotic.

Antivirals

Viral infections that cause conjunctivitis are sometimes treated with antiviral medicated eye drops such as Trifluridine and Idoxuridine. Such viral infections can include:

• Canine herpesvirus

Although this type of therapy is available, it is not always recommended.

Surgery

A surgical procedure may be needed if conjunctivitis developed due to an eye condition such as:

• Blocked tear ducts
• Eyelid or eyelash disorders
• Severe trauma

Surgery might be followed up with antibiotics or other treatments to ensure everything heals properly. Your dog may also be required to wear an Elizabethan (cone) collar to prevent pawing at the eye (this may be recommended in less intense treatments as well).

Be wary of “home remedies”

Some home remedies that you read about can actually do more harm than good, so it’s always best to check with your vet before beginning serious treatment for any illness or injury that your dog may experience — including pink eye.

Dogs usually recover fully from conjunctivitis, but they should be seen promptly to help prevent any additional eye problems from developing.

Eye conditions such as conjunctivitis can be difficult to prevent in your pet, but there are some precautions you can take to lower the risk. 

• Keep your dog’s eyes clean. Gently remove any debris or normal discharge from the area with a damp paper towel when needed.
• Always wash your hands before and after cleaning your dog’s eyes or administering medicine to prevent the spread of germs.
• Keep your pet’s play area clean to prevent dirt, dust or potential dangers from coming into contact with their eyes.
• Supervise your dog’s play time with other animals and safely intervene if an eye (or other) injury occurs. Seek medical attention right away in the event that an injury does occur.
• If your dog recently had eye surgery or is receiving treatment for an eye illness or injury, be sure to closely monitor their behavior and recovery. If symptoms worsen, contact your vet as soon as possible.

It is important to take your dog to regularly scheduled checkups with your veterinarian to ensure they are in good health. Don’t hesitate to call your vet if you have any concerns about your pet, eye related or otherwise.

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