What is Dry Eye Syndrome?
Dry eye syndrome, or Keratoconjunctivitis sicca (KCS), occurs when there is a deficiency of aqueous tear film over the eye surface and in the lining of the lids. The result of this is extreme drying and inflammation of the cornea and conjunctiva. KCS is quite common in dogs, and females are suspected to be more predisposed to it than males. Severe disease may lead to impaired or complete loss of vision. The canine breeds who are most commonly affected with dry eye syndrome are:
• Cocker spaniels
• Lhasa apsos
• West Highland white terriers
What Are the Causes of KCS?
A dog’s tears are needed to lubricate their cornea and remove debris or infectious agents that may get in contact with the eye. The tear film is a mixture of fatty liquid, water and mucus. Therefore, conditions that impair the ability of the eye to produce a necessary amount of tear film may result in KCS. A common list of these causes includes:
• Systemic diseases including canine distemper virus
• Medications including certain sulphonamides (sulfa drugs)
• Dry nose on the same side as the dry eye
• Drug induced, caused by atropine and general anesthesia
• Chlamydia conjunctivitis
• Breed-related predisposition
What Are the Symptoms of Keratoconjunctivitis sicca?
• Swollen conjunctival blood vessels
• Excessive blinking
• Prominent nictitans (third eyelid)
• Discharge of pus or mucus from eye
• Excessive blinking
• Corneal changes in the blood cells, including pigmentation and ulceration
How is KCS Diagnosed?
The doctor will perform a thorough ophthalmological and physical exam on your dog and will review their background history of symptoms and possible incidents that may have led to KCS. The vet may utilize a Schirmer tear test, which measures tear values and eye wetness—a low value of tears would be an indication of KCS. Additionally, a fluorescein stain, which is a non-invasive dye that shows eye details under blue light, may be used to check the dog’s eye for ulcerations/abrasions.
A sample may also be taken of the aqueous fluid for culture, to determine how severe the bacterial growth is in the eye and to check whether there is an infection that is underlying the KCS.
How is KCS Treated?
Your dog will be treated on an outpatient basis unless there is a secondary disease that calls for hospitalization. Topical medications may be prescribed to compensate for your canine’s lack of tears—please note that you will need to clean your dog’s eyes before this medication is administered, and you must also keep their eyes clean and free of dried discharge.
A topical antibiotic that is placed on the eye may also be prescribed, either as a preventative or to treat a bacterial infection. Additionally, an immunosuppressant drug (topical corticosteroid or cyclosporine) that reduces the activity of their immune system can be used to treat inflammation and swelling. Depending on the underlying diseases that have been brought on this syndrome, other medications may also be prescribed.
In certain instances, surgery may be used to reroute the dog’s aqueous ducts so that saliva can be used to compensate for their lack of tears. However, this procedure is less common since the introduction of cyclosporine.
At PAVG, we are always committed to making sure your pet stays happy and healthy. If you suspect your pet may be suffering from dry eye syndrome, or if you notice any of the above symptoms, please contact us at our following locations: