Tears are essential to keeping the eyes moist and healthy by transporting oxygen to the eyes and removing waste. Tears have three portions: water, oil and mucus.
Keratoconjunctivitis Sicca (KCS) is a common eye condition where the tear glands do not produce enough of the water portion of tears. Therefore, there will be a yellow discharge on the eyes.
This also causes eye irritation, inflammation of the cornea, and possible blindness.
Most commonly, KCS is immune-mediated: the immune system attacks the tear-producing cells.
Other causes include:
- Conditions like distemper, hypothyroidism, or conjunctivitis
- Certain medications
- Trauma to the eye
- Genetic disposition
Both eyes are usually affected with signs such as:
- Thick yellow discharge on the eyes
- Crust around the eye
- Holding the eye closed
- Excessive blinking and rubbing of the eyes
- Painful, red eyes
- Inflamed cornea
If you notice any of these signs, bring your dog to the veterinarian right away. Prolonged dryness of eyes may cause scars on the cornea, which can lead to blindness.
The main diagnostic test your veterinarian will do is the Schirmer Tear Test:
- A strip of absorbent paper is inserted just inside the lower eyelid for 1 minute
- The paper changes color as tears are produced
- Determines the volume of tears produced per minute
Your veterinarian may perform other tests to rule out other conditions:
- Corneal staining: checks for ulcers
- Intraocular pressure (IOP): checks for glaucoma
- Tear duct exam and flushing: checks for proper tear drainage
Treatment of KCS is a life-long medication routine. In most cases, this stops the immune system from attacking the tear glands, and stimulates tear production, protecting the cornea.
If your dog does not respond to medication, your veterinarian may recommend surgery. A saliva-producing gland will be attached to the eye to lubricate it. This may cause excessive tearing.
There is no known prevention for KCS.
With life-long medication, there is a great prognosis.
However, if there is considerable scarring on the cornea, your dog may never regain full vision.