KCS is a disorder of the lacrimal (tear-producing) glands commonly seen in dogs of every age, though more often in older dogs. Signs of the disease can include a mucoid discharge, redness, squinting, progressive loss of vision (through scarring and pigmentation), and the development of corneal ulcers. Lhasa Apsos are one of several breeds known to have a predisposition to KCS so we as responsible breeders must make every effort to recognize and understand the disease. Our position as authorities in this breed obligates us to have at least a rudimentary understanding of the health problems that can be encountered in the Lhasa Apso. Not only are our own dogs dependent on the knowledge we accumulate, pet owners often come to us seeking advice about the health and well-being of their dogs, and many rescue situations require decisions based on some veterinary knowledge. Understanding KCS today may save your dog's sight tomorrow.
Causes of KCS
1) *Auto-immune disease - antibodies are produced which actually destroy the lacrimal gland
2) *Infection - chronic conjunctivitis (often caused by allergies) will damage tear glands and ducts. Chronic eye conditions stemming from poor head conformation would include:
b. Abnormal head conformation (as above) can predispose the Lhasa Apso to the malfunction (and possibly the total absence) of the naso-lacrimal ducts, the function of which is to allow excess tears to drain into the nasal cavity. Bacterial infections are the inevitable result of the constant overflow of tears into the facial hair. Face-rubbing to relieve the discomfort would further expose the eye to corneal injury.
4) *Hormonal imbalance - hypothyroidism, diabetes mellitus, Cushings Disease
5) Drug induced - anaesthesia, or possibly the circulatory interruption during surgery
6) Drug toxicity - some sulfa drugs may trigger KCS in susceptible breeds
7) Congenital - sometimes outgrown
8) Removal of third eyelid - should be sutured down if torn loose, not removed
9) Disease - chronic kidney ailments, uterine infections can cause temporary tear suppression
*May have a hereditary component in susceptible breeds.
Diagnosis of KCS
1) Schirmer tear test -strip of filter paper under lower eyelid 1 minute, normal tear production 15-25mm.
Underlying cause should be determined if possible. Management may consist of one or more of the following drug therapies:
1) Cyclosporine drops - 2% in olive or corn oil base (suppresses immune response, dissolves pigmentation)
2) Optimmune ointment - 0.2% cyclosporine in petroleum base
3) Pilocarpine - stimulates sympathetic nervous system to produce tears (also causes drooling)
4) Antibiotics - for secondary infections/corneal ulcers
5) Corticosteroids - to reduce inflammation, pigmentation, scarring. Inhibits healing, use with caution!
6) Artificial tear preparations - drops or ointment, to supplement low tear production
7) Appropriate medication for hormonal disorders/chronic allergies/ear infection
The majority of cases respond well to medical treatment. Many cases can be resolved by treatment of the underlying cause. The use of cyclosporine not only stimulates tear production, over time it will also dissolve existing pigmentation on the cornea, thereby restoring vision to those dogs so afflicted. A small percentage of dogs do not respond to drug therapy. Parotid duct transposition surgery may then be considered . This surgery re-routes the duct of the parotid salivary gland so that the salivary secretions enter at the lower eyelid rather than into the oral cavity.
Ed. Note: Among genetic factors predisposing to eye injury and secondarily to dry eye are large protruding eyes, and eyes unprotected by a prominent malar complex. All Lhasa breeders should try to breed the head conformation that is healthy as well as correct for the Lhasa Apso.