Keratoconjunctivitis Sicca
Is Your Pet Suffering from Dry Eye?
Keratoconjunctivitis sicca (KCS) – Commonly referred to as dry eye – is an ophthalmic condition frequently observed in dogs. KCS is characterized by dryness and/or inflammation of the cornea and surrounding tissues. While the term “dry eye” may not sound all that serious, it can cause severe discomfort in your pet and lead to more serious complications including permanent blindness.
The cornea is the clear, outer shield of the eye. To remain healthy, it requires fluids and nutrients which are supplied by three glands (lacrimal, third eye, meibomian). KCS is caused by inadequate production of these aqueous materials (e.g., fatty lipids, water, mucus) by the tear film.
In layman's terms, there either aren’t enough tears or the quality of the tears themselves provide insufficient nutrients or oxygen for the tissues in your dog’s eyes to remain healthy. The result can be anything from corneal irritation and hyperpigmentation to bacterial infection and ocular pain. In the most extreme cases, the condition can progress to severe corneal opacities and blindness.
Symptoms
KCS stems from either decreased healthy tear production or excessive tear evaporation. Deprived of these necessary nutrients, your dog may experience significant discomfort and begin exhibiting excessive blinking, or red irritated eyes.
One of the chief signs of KCS is overproduction of greenish mucus around the eyelids. The mucus-producing gland of the tear film goes into overdrive trying to produce something to cover the surface of the eye. This creates a breeding ground for bacteria which can lead to infection.
Other symptoms include:
Causes
Any condition that inhibits your dog’s ability to produce sufficient tears can lead to KCS. Some of the leading causes include:
At Evergreen Animal Clinic here in Santa Maria, we’ll review your pet’s medical history, conduct a routine ophthalmic examination, look for clinical signs, and perform one or more diagnostic tests to confirm whether your pet is experiencing KCS..
These tests are important because KCS is often misdiagnosed as bacterial conjunctivitis and treated with topical antibiotics. Under this scenario, your dog might appear to improve, but the symptoms would likely reappear within a few days or weeks.
Common Tests
The most common test we use is the Schirmer Tear Test (STT) which measures your pet’s tear production. A soft strip of wicking paper is placed under your dog’s lower eyelid for one minute to measure the amount of tear film produced.
We also use corneal staining to check for corneal ulcers. We place green fluorescein stain on the eye to evaluate the health of the corneal surface. This allows us to visualize scratches and abrasions on the clear corneal surface.
An intraocular pressure test (tonometry) is used to determine if glaucoma is present, and we may use a flushing technique to ensure normal tear drainage. Finally, we may take a culture to evaluate the health of your dog’s conjunctival cells to look for signs of infection.
Breeds More Likely to Develop KCS
Treatment
We try to accomplish several different objectives when treating KCS, including addressing the underlying inflammatory process, reducing the growth of bacteria, and replacing the lost tear film.
Traditionally, veterinary clinics treated KCS with eyedrop solutions to replace tears, but these don’t provide long-term results. That’s because they don’t have any effect on the underlying inflammatory process that causes KCS, and they don’t replicate the nutrient composition of natural tears.
We now utilize immunosuppressant medications, such as cyclosporine or tacrolimus, to treat KCS. They come in the form of eye drops or ophthalmic ointments that help reduce inflammation and stimulate your dog’s own lacrimal glands to produce tears.
The medications work in about 80% - 90% of dogs, with maximal tear production returning at roughly four to six weeks. These medications need to be administered (usually twice daily) for the rest of your pet’s life. In about 5% of cases dogs will have complications with the medications, including allergic reactions or conjunctivitis.
There are surgical options in cases where medication isn’t effective, including a parotid duct transposition in which a salivary duct from your dog’s mouth is relocated to its eye, but this is less common.
Schedule An Appointment
Keratoconjunctivitis sicca can be a little frightening when you don’t know what’s happening to your beloved pet’s eyes, but it is treatable. If you’re not sure what’s going on with your pet’s eyes, schedule an appointment, and we’ll help put your mind at ease.
The cornea is the clear, outer shield of the eye. To remain healthy, it requires fluids and nutrients which are supplied by three glands (lacrimal, third eye, meibomian). KCS is caused by inadequate production of these aqueous materials (e.g., fatty lipids, water, mucus) by the tear film.
In layman's terms, there either aren’t enough tears or the quality of the tears themselves provide insufficient nutrients or oxygen for the tissues in your dog’s eyes to remain healthy. The result can be anything from corneal irritation and hyperpigmentation to bacterial infection and ocular pain. In the most extreme cases, the condition can progress to severe corneal opacities and blindness.
Symptoms
KCS stems from either decreased healthy tear production or excessive tear evaporation. Deprived of these necessary nutrients, your dog may experience significant discomfort and begin exhibiting excessive blinking, or red irritated eyes.
One of the chief signs of KCS is overproduction of greenish mucus around the eyelids. The mucus-producing gland of the tear film goes into overdrive trying to produce something to cover the surface of the eye. This creates a breeding ground for bacteria which can lead to infection.
Other symptoms include:
- Squinting, blinking excessively or holding the eyes shut
- Painful, red and/or irritated eyes
- A dull, lusterless appearance
- Increased mucus discharge
- Patchy, dry areas or ulcerations on the corneal surface
- Blepharospasm (i.e., abnormal contraction of the eyelid muscles)
- Corneal hyperplasia (e.g., bulging), vascularization or pigmentation
- Corneal mineralization
- Corneal rupture
Causes
Any condition that inhibits your dog’s ability to produce sufficient tears can lead to KCS. Some of the leading causes include:
- Immune-mediated diseases that attack the body’s platelets, red blood cells (i.e., anemia) or lacrimal adenitis (i.e., inflammation of the lacrimal gland)
- Seborrheic or atopic dermatitis and rheumatoid arthritis are frequently associated with KCS
- Congenital, neurologic or metabolic conditions
- Systemic diseases such as canine distemper virus
- Medications (e.g., sulfa-containing antibiotics, non-steroidal anti-inflammatories, atropine)
- Hypothyroidism and diabetes
- Nervous system influences of an inner ear infection (i.e., neurogenic KCS)
- General anesthesia and analgesics (e.g., xylazine, medetomidine, and butorphanol) which temporarily decrease tear production
At Evergreen Animal Clinic here in Santa Maria, we’ll review your pet’s medical history, conduct a routine ophthalmic examination, look for clinical signs, and perform one or more diagnostic tests to confirm whether your pet is experiencing KCS..
These tests are important because KCS is often misdiagnosed as bacterial conjunctivitis and treated with topical antibiotics. Under this scenario, your dog might appear to improve, but the symptoms would likely reappear within a few days or weeks.
Common Tests
The most common test we use is the Schirmer Tear Test (STT) which measures your pet’s tear production. A soft strip of wicking paper is placed under your dog’s lower eyelid for one minute to measure the amount of tear film produced.
We also use corneal staining to check for corneal ulcers. We place green fluorescein stain on the eye to evaluate the health of the corneal surface. This allows us to visualize scratches and abrasions on the clear corneal surface.
An intraocular pressure test (tonometry) is used to determine if glaucoma is present, and we may use a flushing technique to ensure normal tear drainage. Finally, we may take a culture to evaluate the health of your dog’s conjunctival cells to look for signs of infection.
Breeds More Likely to Develop KCS
- American Cocker Spaniel
- Bedlington, Boston, West Highland White and Yorkshire Terriers
- Bloodhound
- Cavalier King Charles, English Cocker and English Springer Spaniels
- English Bulldog
- Lhasa Apso
- Miniature Schnauzer
- Pekingese
- Pug
- Samoyed
- Shih Tzu
Treatment
We try to accomplish several different objectives when treating KCS, including addressing the underlying inflammatory process, reducing the growth of bacteria, and replacing the lost tear film.
Traditionally, veterinary clinics treated KCS with eyedrop solutions to replace tears, but these don’t provide long-term results. That’s because they don’t have any effect on the underlying inflammatory process that causes KCS, and they don’t replicate the nutrient composition of natural tears.
We now utilize immunosuppressant medications, such as cyclosporine or tacrolimus, to treat KCS. They come in the form of eye drops or ophthalmic ointments that help reduce inflammation and stimulate your dog’s own lacrimal glands to produce tears.
The medications work in about 80% - 90% of dogs, with maximal tear production returning at roughly four to six weeks. These medications need to be administered (usually twice daily) for the rest of your pet’s life. In about 5% of cases dogs will have complications with the medications, including allergic reactions or conjunctivitis.
There are surgical options in cases where medication isn’t effective, including a parotid duct transposition in which a salivary duct from your dog’s mouth is relocated to its eye, but this is less common.
Schedule An Appointment
Keratoconjunctivitis sicca can be a little frightening when you don’t know what’s happening to your beloved pet’s eyes, but it is treatable. If you’re not sure what’s going on with your pet’s eyes, schedule an appointment, and we’ll help put your mind at ease.