Dogs eyes, like ours, require constant lubrication from tear production. Without this lubrication the cornea (clear centre of the eye) becomes very inflamed and painful, causing Keratoconjunctivitis Sicca (KCA).  KCA, or dry eye, affects approximately 1% of the canine population. Many breeds are predisposed to primary KCS including cocker spaniels, west highland white terriers, Cavalier King Charles Spaniels, Boston terriers, miniature schnauzers, Pekingeses, Lhasa Apsos and brachycephalic breeds, such as the British bulldog.


  • Immune mediated disease: when the immune system attacks the tear glands and tear production diminishes. This is the most common cause of canine KCS.
  • Idiopathic: is a fancy medical way of saying “we don’t know why”, it just happens.
  • Congenital: Pugs, Chihuahuas and Yorkshire Terriers maybe born with under-developed tear producing glands.
  • Other less common causes include: drug induced, infection, trauma or surgery to the area.


The most common clinical signs associated with KCS are:

  • Eye discharge: thick ropey mucoid discharge is present. As the tear film is missing its aqueous layer, a thick stringy mucus accumulates.
  • Blepharospasm: squinting or closure of the eyelids and is the result of discomfort.
  • Corneal pigmentation and vessel formation: with chronic dryness the clear surface of the eye will become brown and discoloured.
  • Corneal ulceration: can occur secondary to dry eye and will present with a red/blue painful eye.
  • Dry nostrils: occasionally the nostril can be dry on the side of the affected eye as the tears drain via the nose.


The diagnosis of KCS is relatively straightforward. While undergoing a full eye exam your veterinarian will then perform a Shirmer Tear test. This is a non-invasive evaluation of the amount of tears produced using a dye impregnated strip of litmus paper hooked over the lower eyelid for 60sec.


Primary treatment for KCS is medical with surgical options reserved for patients non-responsive to topical therapy. In most patients topical therapy is required indefinitely for the life of the patient.

  • Tear Stimulation
    • Cyclosporine is a medication to normalise the immune system. It blocks the inflammatory cells doing damage to the lacrimal gland. It is directly treating the underlying cause and stimulates tear production. It is available as an ointment or eye drop applied daily.
    • Tacrolimus has a similar but more potent action than cyclosporine. We use it in patients that are unresponsive to cyclosporine.
  • Tear Replacement: These medications are available as solutions, gels and ointments and aim to provide lubrication until tear stimulants are effective. Sometimes lifelong tear replacements are required when there is poor response to the stimulants.
  • Antibiotics and Ulcer Treatment: Secondary bacterial infections are very common, we use eye medications to resolve this when present. It is also common to have corneal ulcers present in KCS affected patients. These are also treated with topical antibiotics, pain relief, atropine and sometimes surgery is required if non-healing.
  • Surgical Management: Surgical management of KCS is only considered if all medical treatment has been trialled with no response to therapy. The surgery of choice is a parotid duct transposition which is a very intricate procedure that redirects saliva from the mouth into the eye socket. Surgery is performed by a specialist ophthalmologist as there is potential for post op complications.

Prognosis and monitoring

The prognosis for KCS depends on the underlying cause and the patient’s response to treatment.

If there is a poor response to medical treatment then it is far more likely that vision will be affected or even lost through the chronic inflammatory changes to the cornea.

Most patients will require diligent lifelong therapy for successful management and regular veterinary checks every 6-12 months to assess the effect of treatment and progression of the disease.