What Is Pink Eye?
Pink eye, known as conjunctivitis in the veterinary community, is quite common in dogs. Like pink eye in humans, conjunctivitis in dogs typically causes red, inflamed eyes. This gives the disease its nickname, "pink eye."
The scientific name, conjunctivitis, quite literally means inflammation of the conjunctiva. The conjunctiva is the tissue that lines your dog’s eye, eyelids, and third eyelid, and when this gets red and irritated, it could mean that your dog needs to see the veterinarian for conjunctivitis.
What Are the Symptoms of Pink Eye in Dogs?
This inflammation leads to the symptoms we commonly associate with pink eye in humans. Your dog’s eyes may produce a discharge that can be clear and watery, or a mucous discharge, or even a purulent mucous discharge that can look yellowish or green. Squinting or excessive blinking may also occur, and many dogs develop red, swollen eyelids. The "White art" or sclera may become congested as well.
Conjunctivitis usually affects both eyes, but it can affect just one, depending on the cause. In some cases, your dog’s pink eye could be accompanied by other symptoms, like nasal discharge, coughing, or sneezing. Conjunctivitis symptoms could also be a sign of a more serious eye problem, so make sure you contact your veterinarian if your dog starts showing symptoms of eye discomfort.
What Causes Pink Eye in Dogs?
Conjunctivitis can be a disease all on its own, or it can be a symptom of another eye disease.
Bacterial and viral infections are the most frequent causes of pink eye in dogs, followed by environmental irritants, such as smoke, and allergens. If conjunctivitis occurs in only one eye, it may be the result of a foreign object, inflammation of the tear sac, or dry eye.
Here are some of the other causes of conjunctivitis in dogs.
- Foreign bodies, such as plant matter, dust, dirt, or debris
- Certain parasites of the conjunctiva or eyelids
- Defects of the eyelid or eyelashes, like entropion (abnormal eyelids) or eyelash disorders such as distichia (abnormal eyelashes)
- Inflammation of the tear duct
- Dry eye
- Tumors of the eye and eyelid
- Immune-mediated conditions such as allergic conjunctivitis
How Is Pink Eye in Dogs Diagnosed?
Your dog may have one or all of the symptoms of pink eye, but that is usually not enough to provide an accurate diagnosis of your dog's condition.
Your veterinarian may perform one or more diagnostic tests to determine the cause of your dog’s pink eye in order to develop the best treatment plan.
For example, if your dog’s pink eye is a secondary symptom of a condition such as dry eye or a tumor, treating the pink eye itself will not be enough to resolve the problem.
Your veterinarian will probably perform a detailed examination of your dog’s eyes, eyelids, and surrounding structures using an ophthalmic lens. He or she may also test your dog’s tear production using Schirmer tear strips, perform a stain test to look for corneal damage, and measure your dog’s eye pressure to make sure he does not have a condition such as glaucoma or uveitis, which is when the uvea (the dark tissue at the front of the eye that contains blood vessels) becomes inflamed and causes pain.
If these tests are not definitive, or if your veterinarian deems it necessary, a bacterial culture, nasolacrimal duct flushing (the nasolacrimal duct is the structure ensuring tear drainage from the surface of the eye to the nose), cytology (the microscopic examination of cells) of the conjunctiva, biopsy, or even allergy testing can help provide a diagnosis.
How Is Pink Eye in Dogs Treated?
You may remember being treated with eye drops if you have ever had pink eye. In many cases, eye drops are an important part of treating pink eye in dogs, and your veterinarian will show you how to safely administer the drops.
The best treatment plan for your dog’s pink eye will depend on the underlying cause. Your veterinarian may prescribe topical eye drops to reduce inflammation and fight any infection, or in some cases to stimulate tear production and lubricate the surface of the eye.
These eye drops can contain antibiotics, topical steroids, or compounds that stimulate tear production.
If the cause of your dog’s pink eye is a deformation or abnormality, such as distichiasis or entropion, your dog may require a surgical procedure to correct the problem.
Sometimes, a systemic medication may be required to treat the underlying condition, especially if the cause is viral or bacterial.
Can Pink Eye Be Prevented in Dogs?
Some causes of pink eye are nearly impossible to prevent, for example dry eye. Breeders can perform eye exams on the dogs they would like to breed to make sure they do not pass on inherited conditions like entropion.
Owners should keep their dogs up-to-date on vaccines such as distemper to help prevent some of the viral causes of conjunctivitis. You can also supervise dogs at play to prevent trauma and discourage brachycephalic dogs from engaging in behaviors that might lead to eye damage, such as sniffing around thorn bushes or provoking cats. Also, if you're going on a road trip with your dog, he should always be safely secured in a crate or car seat. You should never let him stick his head out of the window of a moving car for numerous reasons, one of which being that flying dirt and debris could enter his eyes.
The best thing you can do to help your dog avoid pink eye is to take her into the veterinarian’s office when you first notice symptoms. This could help reduce the severity of the condition and get your dog's eyes back on track.