Keratoconjunctivitis Sicca in Dogs

Keratoconjunctivitis sicca can cause the dog’s own immune system to target and break down the lacrimal glands. If left untreated, the lacrimal glands are completely destroyed and can no longer produce tears. The damage to the lacrimal glands is irreversible. KCS may develop quickly or more slowly, in one or both eyes. 

The eye needs tears to maintain the health and transparency of the cornea. Tears are meant to lubricate, cleanse and carry vital nutrients to the eye. Without the ability to produce tears the eye becomes dry and is more susceptible to infections. Keratoconjunctivitis sicca is a painful and uncomfortable condition which will lead to corneal ulceration, scarring and eventually blindness.

Breeds predisposed to get KCS are the English Bulldog, Lhasa Apso, Pug, Bloodhound, Bull Terrier. Cocker Spaniel, Schnauzer, Chihuahua, Pekingese, Miniature Poodle, Yorkshire Terrier, Dachshund, Welsh Terrier, English Setter, and the Shih Tzu.

Keratoconjunctivitis Sicca (KCS) is a common condition in dogs that is also referred to as dry eye.  KCS causes the inadequate production of tears resulting in the inflammation of the lacrimal gland, cornea and the conjunctiva.

Keratoconjunctivitis sicca can cause different symptoms in canines such as:

• Your dog will paw and scratch at his eyes
• The cornea may appear dull, dry and opaque
• Eye redness 
• Eyelids are swollen
• Thick yellow-green ocular discharge
• Sensitivity to light
• Eyelid twitching
• Excessive blinking

Keratoconjunctivitis Sicca (KCS) can be caused by the following:

• Immune-mediated cause
• Hereditary predisposition
• Eye trauma
• The use of sulfonamide drugs can be toxic to the lacrimal glands.
• Surgical removal of the lacrimal gland of the third-eye (a procedure done treating cherry eye)
• Congenital condition
• Secondary to  hypothyroidism, canine herpes virus, distemper virus, and diabetes mellitus

Your veterinarian will take a complete history of your dog’s health.  It can be helpful to write down a log of your dog’s health history which should include when the current symptoms and frequency started, before meeting with the veterinarian.  Diagnosis will be based on health history, physical exam and diagnostic procedures.  

Your veterinarian will perform a thorough physical and ophthalmological examination of your dog. He will look into your dog’s eyes with a hand held instrument called an ophthalmoscope. 

The most common diagnostic test used to check decreased tear production is the Schirmer tear test (STT).  This is a simple test which uses a special soft wicking paper placed in the dog’s lower eyelid to measure the amount of watery tear production.  The veterinarian may also performed corneal staining to check for corneal ulcers. Sometimes rose bengal stain may also be used to check the health of the outer layer of the cornea. Additional diagnostic tests may include tear duct examination and intraocular pressure to determine if glaucoma is present. Your veterinarian may also recommend cytology or cultures to check the conjunctival cells and to rule out bacterial infections.

KCS is usually handled in an outpatient basis.  The objectives to treating this condition are to stimulate tear production (if still functioning) and to replace tear film, control inflammation, treat eye infections, and resolve any ulcers on the cornea.

Medications/Treatments

Cyclosporine and tacrolimus are two common ophthalmic medications prescribed to stimulate tear production. If these lacro-stimulants are effective in stimulating tear production, treatment usually is for the rest of the canine’s life. Cleaning the eyes several times a day with a warm washcloth or gauze may help stimulate tear film production. Your veterinarian may also recommend topical antibiotics and anti-inflammatory medicine.  

If your dog’s lacrimal glands are completely destroyed, he will need to have tear substitutes called artificial tears applied regularly to help keep the eye lubricated and to reduce discomfort. 

If your pet was diagnosed with a bacterial infection or corneal ulceration, he will be prescribed antibiotics.  You veterinarian may also recommend anti-inflammatory that are nonsteroidal, or corticosteroids.  

Surgical Procedures

In some severe cases veterinarians may suggest a parotid duct transposition which involves repositioning the salivary duct so that it can secrete saliva into your canine’s eye. This procedure has some risks and possible complications. The procedure may cause too much fluid being produced and saliva crystals may form in the eye. There is also the possibility that the saliva can irritate the dog’s eye. 

Another surgical option is a permanent partial tarsorrhaphy, this involves suturing parts of the lower and upper eyelids together. This is done to help lower the exposure of the eye surface to the elements and to conserve tears.

KCS requires life-long medical care. Follow-up visits to your veterinarian will be necessary to monitor how your dog is responding to the medication. It is very important in treating KCS to consistently apply the medication as prescribed.  Do not stop or reduce it even though your dog’s eye may look better. Stopping administering the medication will allow the inflammation to return. It is critical that you follow your veterinarian’s treatment plan.