Tears provide more than just lubrication for the eyes. Tears possess anti-bacterial properties and help flush out irritants and infectious agents in a dog’s eyes. Since the outer part of the eye lack the blood supply that normally brings nourishment, tears contain a variety of important substances like sugar, salt, protein and oxygen that work together to nourish the eye.
When there is insufficient amount of tears, a pug’s eyes can become irritated and the conjunctiva appears to be red. When left unchecked, the dog’s cornea will turn brown and there is a yellowish ocular discharge. At this stage, there is a high chance of vision loss.
Tears are watery secretions of the lacrimal glands. Dogs have two lacrimal glands—one in its nictitating membrane (third eyelid) and the other one above the eye.
Keratoconjunctivitis sicca refers to a condition where the eye is dry or devoid of tears. “Kerato” means the cornea while “conjunctiva” refers to the membranes lining the eye socket. “Conjunctivitis” refers to the inflammatory condition while “sicca” means dry. In effect, Keratoconjunctivitis sicca simply means an inflammation of a dry cornea and conjunctiva.
Water composes 95% of the tear volume. Once there is deficiency in the water content of tears, what’s left are oil and mucus which you can see as the yellowish eye discharge.
There are many important predisposing factors and actual causes of eye dryness in dogs. These include—
A definite diagnosis of Keratoconjunctivitis sicca is accomplished using the Schirmer Tear Test. Some owners might just dismiss the early signs as a simple case of conjunctivitis however, there is a need to bring your dog to the vet for a thorough check and diagnosis.
The Schirmer Tear Test involves placing a strip of special paper inside the lower eyelid of the eye for about 60 seconds. The moisture from the dog’s tears will wet the paper. After 60 seconds, the length by which the paper strip has been moistened by the tears is then measured.
15 mm or more Normal
11-14 mm Borderline
10-6 mm Dry
5 mm or less Severely dry
The old method of treating KCS involves the application of artificial tear formulas and agents that can dissolve mucus. Although these preparations can help alleviate the symptoms, it is often impractical to administer frequently.
A new treatment regimen involves cyclosporine therapy which aims to control the destruction brought about by the immune-mediated condition. When the tissue destruction is suppressed, tear production is restored. Compared to the older forms of treatment, Cyclosporine can conveniently be administered once or twice a day only.
Pugs which have been found to have very dry eyes ( 2 mm or less) often have favorable prognosis when given cyclosporine. However, it is relatively expensive but it is worth the outcome.
In case your dog is not responding as well as it should, it’s advisable to see your veterinarian for there might be a need to increase the dosage or concentration. Artificial tears and antibiotic preparations may also be prescribed by your vet to prevent secondary bacterial infections.