Keratoconjunctivitis sicca, also called dry eye syndrome, is a condition that many dogs can develop. It’s more common than most pet owners realize, and while it doesn’t sound like it could be all that dangerous, dry eye syndrome can actually have serious repercussions for dogs. In this guide to keratoconjunctivitis sicca, we will cover everything you need to know about this condition, including:
- Causes of keratoconjunctivitis sicca in dogs
- Common keratoconjunctivitis sicca symptoms
- Diagnosis of keratoconjunctivitis sicca
- Available keratoconjunctivitis sicca treatment
- Preventing keratoconjunctivitis sicca
If you have a dog, particularly a smaller breed like a Cocker Spaniel, a Westie, or a Shih Tzu, or a bulldog, this guide could help you identify and treat this condition.
What is Keratoconjunctivitis Sicca?
Before we dive into what you need to know about this condition, let’s define what exactly it is. Keratoconjunctivitis sicca is a condition in which the tissue around a dog’s eye becomes inflamed because it is too dry. The dog’s tear gland isn’t able to produce enough tears to keep the eye tissue hydrated. This condition happens in about 1% of dogs across North America – which would mean that in the United States alone, nearly 900,000 dogs are affected by keratoconjunctivitis sicca every year.
Causes of Keratoconjunctivitis Sicca in Dogs
There are quite a few reasons that a dog can develop keratoconjunctivitis sicca. Some dog breeds are simply more likely to develop the condition due to genetics, including Cocker Spaniels, Bulldogs, Shih Tzus, and Westies, Yorkies, Pugs, and toy breeds. Other reasons that a dog could develop dry eye syndrome are extremely varied:
- It could be a symptom of another systemic disease, such as distemper.
- It could be a response to having an x-ray near the eye.
- It could be related to bacterial Chlamydia infection.
- It could be caused by having a reaction to anesthesia.
- It could be related to other chronic eye issues.
- It could be related to immune system deficiencies.
- It could be caused by nerve damage.
- It could be caused by a procedure that removes the third eyelid in certain breeds.
- Dogs with hypothyroidism are more prone to developing keratoconjunctivitis sicca.
In other words, any procedure, illness, or condition that could affect the eyes or the immune system can lead to keratoconjunctivitis sicca. The most common cause of dry eye syndrome is any disease that attacks the immune system, which is also referred to as a meibomian gland dysfunction. In fact, 86% of all dry eye syndrome cases are caused by this problem. In this situation, the immune system gets “confused’ and attacks the glands that produce tears in the eye. This is most likely a genetic condition passed down from parents.
In addition to the dogs listed above, the breeds that are most likely to develop keratoconjunctivitis sicca are:
- Bloodhound
- Boston Terrier
- Lhasa Apso
- King Charles Spaniel
- Pekingese
- Samoyed
- Schnauzers
There are seven areas of the eye that are affected by this disease:
- The tear film
- The lacrimal apparatus
- The drainage system
- The eyelids
- The cranial nerve V
- The tarsal conjunctiva
- The cranial nerve VII
If any of these areas of the eye are abnormally developed, they could also lead to dry eye syndrome.
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Common Keratoconjunctivitis Sicca Symptoms
The most common signs of keratoconjunctivitis sicca are red or irritated eyes. However, the condition can cause symptoms that range from mild to extremely serious. Here are some of the other symptoms of dry eye syndrome:
- Discharge from the eye, especially thick, yellow discharge
- Excessive blinking or being unwilling to open the eyes
- Squinting
- Reoccurring eye injuries
- Ulcers in or around the eye
- Dark film covering the eyes
- Constantly scratching or rubbing at the eye
- Eyes that appear excessively teary all the time (a reflex to the fact that the eye is constantly dry)
- Being unable or unwilling to look directly at light
- Visible, swollen blood vessels on the entire cornea
- Dull eyes that appear dry or hard
- Scarring tissue around the eye
- Tissue around the eye pulling away from the eye
- Very prominent third eyelid
- Loss of vision or impaired vision
In some cases, dry eye syndrome that leads to infections in or around the eye could lead to other issues in the body. Infections can spread to other systems of the body, and if the keratoconjunctivitis sicca is related to immune issues, this could mean that the dog could sick in other ways.
Diagnosis of Keratoconjunctivitis Sicca
There are three main things that a vet will do to diagnose keratoconjunctivitis sicca:
- A look at the dog’s medical history
- An examination of the symptoms
- Tests of tear production
So first, the vet will gather all the evidence for keratoconjunctivitis sicca based on the symptoms that are being seen. They’ll ask you all about the dog’s medical history, as well as the history of the dog’s parents. Issues that your dog may have once had, that they haven’t had recently, could be signs that your dog has this issue.
Next, your vet will perform a test of the tear production. There are four main tests that can be done. The first one is called a Schirmer tear test, or STT. This test measures how many tears are produced over the span of a minute. The second test is called an IOP, or intraocular pressure test, to determine if there is glaucoma present. The next test method is to flush the eye and watch how tear drainage happens. Finally, the last test involves using a stain to check the cornea for ulcers. The stain is added to the eye, and it will illuminate ulcers that are causing the problem when a blue light is shined on the eye.
If none of these tests result in a definitive diagnosis, the vet may also take a swab from the tear duct to test for bacterial infections. If a dog has a very low Schirmer test result, a dysfunctional immune system, or there is evidence that the dog is also not producing a sufficient amount of saliva, these things point to dry eye syndrome.
With all of this information together, veterinarians are able to determine whether a dog has keratoconjunctivitis sicca. The information they gather from your medical history information can help them determine the most likely cause of the syndrome, which is important for determining what type of treatment would be best.
During the diagnostic procedure, the vet will also rank the keratoconjunctivitis sicca from one to four. A one means that your dog has a few visual symptoms and are in some discomfort; a two means that your dog only experiences this condition when under stress or in brief episodes; a three means that your dog has chronic episodes of this condition, but it is not constant; and a four means that your dog has this condition in a very extreme, severe way.
Available Keratoconjunctivitis Sicca Treatment
For the most part, treatment for keratoconjunctivitis sicca is based on treating the symptoms, rather than curing the syndrome. While there are things that could be possible permanent fixes, they aren’t as commonly explored. Common treatments include:
- Topical medications like fake tears and eye lubricants, which may be gels, drops, or ointments
- Antibiotics to get rid of infections or prevent infections
- Topical Omega-3 fatty acids
- Topical corticosteroid to treat the swelling or inflamed tissue
- Surgical removal of the third eyelid
If the issue is that the immune system is attacking the tear gland, the dog may require immunosuppressive medication, which is administered as a topical ointment to the eye.
There is a surgical procedure that actually reroutes the tear ducts so that they use saliva to compensate for the lack of tears. This is not a common procedure because saliva can irritate the eyes, and it causes the dog to need ongoing treatment and medication for their rest of their life.
For the most part, gentle daily cleaning and using eye drops to replace the tears every two to six hours is enough to manage the condition. The overall prognosis for dogs that have keratoconjunctivitis sicca is pretty good. It does require lifelong care to prevent the condition from becoming worse, but eye drops and eye cleaning are usually all that is needed to prevent the dog from having pain or other symptoms.
However, like most diseases, the prognosis gets worse the longer the diagnosis is delayed. It is far more likely that a dog will lose their vision or suffer more serious symptoms if they aren’t taken to the vet when the initial signs and symptoms start to show up. If the cornea becomes scarred, for example, there really is no treatment available to prevent the eventual loss of vision.
Any dog that is diagnosed with this condition will need regular monitoring by a vet for the rest of their life. This is to ensure that the condition isn’t getting any worse and that the dog isn’t developing any other infections or more serious symptoms like loss of vision.
Finally, some dogs with dry eye syndrome also need to wear therapeutic glasses that are known as “moisture chamber spectacles”. These are goggles that wrap around the head, and help to not only keep irritants out of the eye and prevent photophobia, but also help to keep moisture in the eye rather than evaporating away.
A few other very advanced options that are not usually performed include:
- Surgical sealing of the tissue around the cornea with adhesive
- Patching any perforation in the cornea
- Surgical occlusion of the drainage system
- Mucous membrane grafting
- Replacing the entire ocular surface lens with a prosthetic
Preventing Keratoconjunctivitis Sicca
For most dogs, keratoconjunctivitis sicca is a genetic condition that cannot be prevented. However, keeping your dog healthy, free of other infections, and preventing or caring for injuries to the eye right away, can help prevent the syndrome from developing through the other common means.
If your dog has some sort of injury or surgery around the eye, be sure that you talk to your vet about what you can do to protect it from getting infected or further irritated. Express your concerns about this syndrome to get some tips on how you can prevent your dog in the specific situation from having more problems with the eyes.
Finally, if you own a dog that is prone to this condition, be sure you ask if the parents or grandparents had any issues with their eyes, and be sure the vet always does a thorough check of the eyes at the dog’s yearly checkup.
To Sum It Up
If you suspect your dog has dry eye syndrome or keratoconjunctivitis sicca, it is important to get to your vet as soon as you can schedule a checkup. If your dog’s eyes water a lot or appear dry and irritated, are swollen, or are producing a discharge, or your dog seems to be struggling with their vision, any of these things could point to some level of keratoconjunctivitis sicca.
This can be only a mildly irritating syndrome that is easily managed with topical drops and antibiotics. However, it can also lead to severe consequences like blindness and other infections. That is why it is important to have your vet check out your dog’s eyes soon if you notice problems.
Try to find out if your dog’s parents had issues with their eyes, or if keratoconjunctivitis sicca runs in the dog’s family. This is a genetic disorder in many cases, especially if you have a dog that is one of the breeds listed above as commonly prone to this condition.
The good news is that a diagnosis of keratoconjunctivitis sicca is not generally life-threatening. While there are no real cures for this condition, it can be treated in a variety of ways that will improve your dog’s quality of life and keep their eyesight healthy as long as possible. The sooner you get your dog to the vet, the more likely it is that the management will be easy to handle.
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Sources:
http://todaysveterinarypractice.navc.com/diagnosis-treatment-of-keratoconjunctivitis-sicca-in-dogs/
https://www.petmd.com/dog/conditions/eyes/c_dg_keratoconjunctivitis_sicca