Keratoconjunctivitis Sicca (KCS), also known as Dry Eye, is a disorder that affects the tear glands in dogs and cats. It causes the tears to contain less of its aqueous layer and more of its mucous layer. This results in the tear glands producing a thick and stringy discharge that causes excessive dryness in the cornea.
KCS is often misdiagnosed as conjunctivitis. Only when the treatments for conjunctivitis fail to work is KCS usually diagnosed. In severe cases, Dry Eye can cause the cornea to become ulcerated to the point that blindness occurs.
Dry Eye and Canines
Dry Eye can afflict any breed of canine at any age, but certain breeds are predisposed to this condition, including Bulldogs, Lhasa Apsos, West Highland White Terriers, and Cocker Spaniels. But in most cases, KCS is the result of some type of trauma to the eye. For example, injuries to the nerves located in the lacrimal glands, or to the tear glands themselves, can cause Dry Eye.
Other causes of KCS include hypothyroidism, canine distemper virus, bacterial blepharitis, conjunctivitis, a congenital absence of the tear glands, surgical removal of the third eyelid, and long-term use of sulfonamide drugs.
Dry Eye and Felines
Keratoconjunctivitis Sicca is rare in felines, but it can occur. In fact, studies suggest that the female sex of the species is more prone to developing KCS than males, with all breeds being of equal risk.
In most cases, KCS in felines is caused by immune-mediated adenitis, traumatic proptosis, general anesthesia, sulfa drug-related toxicity, chronic herpesvirus infection, or chlamydia conjunctivitis.
What to Do if You Detect Symptoms of KCS in Your Pet
KCS has symptoms that can mimic regular conjunctivitis. Typically, pets afflicted with KCS will exhibit excessive blinking, a mucous-like discharge from the eye, a swelling of the tissues that line the eyelids, swollen conjunctival blood vessels, and changes to the affected cornea, including ulceration.
If you believe that your pet may have Dry Eye, do not take the condition lightly. You should take your pet to the veterinarian as soon as possible. The vet will perform a test called the Schirmer tear test. This test involves placing a filter paper strip into the tear pool at the inner corner of the pet’s eye for one minute. The vet will then be able to determine how much of the strip is wetted, which in turn will let the vet know how much tears are being produced by the tear glands.
How Is Keratoconjunctivitis Sicca Treated?
In the past, the administration of artificial tears was the only option available for treating Dry Eye in dogs and cats. But in recent years, the FDA has approved the use of ophthalmic cyclosporine, and this has delivered greatly improved results. Cyclosporine is an immunosuppressive drug that has the ability to reverse the immune-mediated destruction of the lacrimal glands. In most cases, artificial tears and topical antibiotic treatments will continue until the pet’s Schirmer tear test indicates that tear production has returned to adequate levels.
Once a pet develops Dry Eye, treatment with cyclosporine will be life-long. Stopping the treatment will usually result in a return of KCS symptoms in as little as 24 hours, in 90% of dogs and cats. If the pet is suffering from heavy mucous production, then a topical mucolytic agent containing acetylcystine is often prescribed. Only in the absolute worst cases will surgery usually be considered.
Diamondback Drugs offers a variety of pet-friendly formulations for treating Keratoconjuunctivitis Sicca.
How to Prevent Dry Eye in Your Pet
Dry Eye can affect any dog or cat at any age, and it can be caused by a wide variety of factors, many of which are unavoidable. As a result, it can be very hard for a pet owner to take any steps to help prevent their pet from developing KCS. That said, keeping the pet’s exposure to sulfa-based drugs to a minimum can help. You should also make sure your pet is vaccinated against canine distemper, and have your animal seen by their veterinarian at regular intervals.
Author: Giano Panzarella