What is Dry Eye in Dogs and Cats?
Dry eye, medically known as keratoconjunctivitis sicca (KCS), is an inflammation of the cornea and conjunctiva due to insufficient tear production. This condition is common in dogs, affecting approximately 1% of the canine population, particularly those over seven years old. While less frequent, cats can also develop dry eye.
Predisposed Breeds
Certain dog breeds are more susceptible to developing dry eye, including:
- American Cocker Spaniel
- Bulldog
- West Highland White Terrier
- Lhasa Apso
- Shih Tzu
- Yorkshire Terrier
- Pekingese
- Boston Terrier
- Doberman Pinscher
- Dachshund
- Chihuahua
- German Shepherd
Regular eye health monitoring is crucial for these breeds to detect early signs of dry eye.
Symptoms
Clinical signs of dry eye in dogs and cats include:
- Redness and swelling of the conjunctiva
- Pain, often indicated by excessive blinking or squinting (blepharospasm)
- Mucous or mucopurulent discharge
- Superficial corneal vascularization
- Corneal pigmentation and ulcerations
If untreated, the condition can lead to vision loss.
Causes
The majority of dry eye cases are of autoimmune origin. Other potential causes include:
- Congenital factors
- Neurological disorders
- Side effects of medications (e.g., anesthesia, atropine, sulfonamides)
- Surgery involving the nictitating gland
- Radiation therapy
- Systemic diseases such as hypothyroidism, diabetes mellitus, canine distemper, or feline herpesvirus
- Chronic conjunctivitis and blepharoconjunctivitis
Diagnosis
To confirm dry eye, veterinarians perform:
- Schirmer Tear Test: Measures tear production.
- Fluorescein Staining: Detects corneal ulcers.
Treatment
The goal of treatment is to hydrate the eye, stimulate tear production, and prevent infections.
Medical Options
- Cyclosporine: The most commonly prescribed medication, effective in approximately 80% of patients. Tear production is re-evaluated after 4 to 6 weeks to assess efficacy.
- Tacrolimus or Pilocarpine: Alternatives if cyclosporine is ineffective.
- Topical Antibiotics: Recommended in cases of secondary infection.
- Artificial Tears and Lubricating Ointments: Essential, especially during the initial phase of treatment.
In most cases, treatment is lifelong.
Surgical Options
If medical treatment fails, a parotid duct transposition may be considered. This technique redirects saliva from the salivary gland to lubricate the eye. However, it carries risks such as:
- Calcium deposits on the cornea
- Excessive discharge
- Facial dermatitis
- Occlusion of the parotid duct
Fortunately, this procedure is rare due to the effectiveness of cyclosporine in many cases.
Conclusion
Dry eye is a serious condition requiring early diagnosis and appropriate treatment. Prompt management helps preserve your dog’s comfort and vision. If you have any questions or wish to schedule a consultation, please contact our veterinary clinic today.
