Keratoconjunctivitis Sicca KCS, Dry Eye
Learn what the condition is, how it may be detected early, how it is treated or managed, and which breeds or species are linked to it.
Condition snapshot
A concise guide to the condition’s pattern, detection, management and urgency.
This snapshot is a general guide, not a diagnosis or treatment plan. New, severe or worsening signs require veterinary assessment.
About the condition
Keratoconjunctivitis sicca, commonly called dry eye, occurs when the eye does not produce enough of the watery component of tears. Tears lubricate the cornea, deliver nutrients and antimicrobial substances, and wash away debris. When production falls, the surface becomes dry, inflamed and vulnerable to infection and ulceration.
The most common canine form is immune mediated, in which the dog’s immune system progressively damages tear-producing glands. Breed predispositions are recognised, although the inheritance is not fully defined. Dry eye can also develop after certain medications, severe infection, nerve dysfunction or surgical removal of the third-eyelid gland. One or both eyes can be affected.
Early signs include sticky or stringy discharge, redness, frequent blinking and rubbing at the eyes. As the condition progresses, the cornea can lose its normal shine, become pigmented and develop blood vessels or scar tissue. Recurrent corneal ulcers are painful and can threaten vision. Some dogs initially appear to have repeated conjunctivitis because the thick discharge resembles infection.
The rest of the eye is examined for corneal damage, infection and causes of secondary dry eye. Tear values are interpreted together with clinical signs because mild results can vary.
Untreated KCS is a chronic source of pain and can cause permanent corneal change. Early treatment is important because medications that stimulate the tear glands work best while functional gland tissue remains. Once severe gland destruction has occurred, maintaining a comfortable tear film can become more difficult.
The amount of remaining tear-gland function matters. Early disease is often easier to control because functioning gland tissue can still respond to tear-stimulating medication, whereas longstanding severe dryness can leave permanent pigment, scarring and a greater risk of recurrent corneal injury.
Early detection is particularly valuable because tear-stimulating treatment is more successful before immune-mediated destruction of the glands becomes advanced.
Screening & Early Detection
Routine eye examination is the main approach to early detection, particularly in breeds predisposed to immune-mediated dry eye. The Schirmer tear test is simple and inexpensive and may be included when a dog has recurrent discharge, redness, corneal pigmentation or a history that raises concern. Its value as a universal screening test in every symptom-free dog is less certain because tear production varies between individuals and circumstances.
Seek assessment when eye discharge becomes thick or sticky, the eyes lose their normal shine, the dog rubs its face or recurrent “conjunctivitis” keeps returning. Fluorescein staining checks for corneal ulcers, and examination of the eyelids and third-eyelid gland helps identify contributing abnormalities.
Medication history matters because some drugs can reduce tear production. Dogs that have had the gland of the third eyelid removed are also at increased risk and deserve ongoing tear monitoring.
A low Schirmer result should be interpreted in context and may be repeated when values are borderline. Significant corneal ulceration or pain requires immediate treatment regardless of the measured tear number.
Diagnosis is made with the Schirmer tear test, which measures tear production using a small paper strip placed inside the lower eyelid.
Treatment & Management
Treatment usually combines stimulation of natural tear production with replacement of moisture at the eye surface. Immunomodulating eye medications such as ciclosporin or tacrolimus are commonly used to reduce immune destruction of the tear glands and improve their function. These medications often take several weeks to produce full benefit and generally need to be continued long term.
Lubricating drops or ointments protect the cornea while tear production remains inadequate. Thick discharge may need gentle cleaning, and bacterial infection or corneal ulceration is treated separately when present. Steroid-containing eye drops must not be used over an active corneal ulcer.
Follow-up Schirmer testing helps determine whether tear production is improving and whether medication needs adjustment. Do not stop treatment because the eye looks better; the underlying immune-mediated process usually returns if therapy is withdrawn.
Dogs that fail to produce adequate tears despite intensive medical treatment may be considered for parotid duct transposition, a specialist surgery that redirects saliva from the mouth to the eye. The procedure can improve lubrication but introduces saliva-related complications and is generally reserved for refractory cases.
With consistent treatment, many dogs remain comfortable and retain useful vision. The most common reason for poor control is inconsistent medication rather than a lack of available therapy. New squinting, sudden cloudiness or pain should be assessed promptly because dry-eye dogs remain susceptible to corneal ulcers.
Breeds or species affected
Bloodhound
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Boston terrier
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British Bulldog
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Bull terrier
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Cavalier king charles spaniel
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Chihuahua
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Pug
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Shar Pei
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Chow chow
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Clumber spaniel
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Cocker spaniel
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Dachshund
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English setter
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Gordon setter
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Kerry blue terrier
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Lhasa apso
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Miniature Poodle
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Miniature Schnauzer
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Pekingese
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Schnauzer (miniature, standard)
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Schnauzer (standard)
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Sealyham terrier
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Shih tzu
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Welsh terrier
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West Highland white terrier
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Yorkshire terrier
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