Keratoconjunctivitis Sicca (Dry Eye) In Cocker Spaniels

Keratoconjunctivitis sicca (also known as KCS or "Dry Eye") is a common disease in dogs (not just cocker spaniels). It is caused by a lack of tear production & can affect one eye or both eyes. Tears provide lubrication, wetting and nourishment to cornea and conjunctiva.

What are the signs of dry eye?

• Thick, sticky/stringy discharge from the eyes
• "Red eye" redness of the conjunctiva due to inflammation & increased blood supply (hyperaemia)
• Opacity to the cornea (the surface is normally clear/bright)
• Affected dogs often cannot open their eyelids fully
• Some dogs rub their eyes

Diagnosis

Diagnosis is confirmed by using a "Schirmer Tear Test". The paper strip is gently inserted into the gap between the eye and eyelid (it does not appear to be uncomfortable for the dog) and absorbs the liquid tears present.

The strip absorbs moisture & measures the amount of tears on the surface of the eye. The strip is left in contact with the eye for 1 minute, the strip is in increments and the level of saturation (from the tears) is recorded i.e. at what level does tear moisture end on the strip (shown as a blue dye). A reading of over 15 on the scale is regarded as normal although many unaffected dogs may only reach 10 - 12 points. Readings of 0 - 5 are indicators of KCS.

Causes of "dry eye"

• An autoimmune disease - the animals own immune system damages the tear producing (lachrymal) tissue
• Lachrymal gland damage due to side-effects of various drugs
• Idiopathic (unknown) causes

How is "dry eye" treated?

It is important that dogs diagnosed with dry eye receive treatment. Inflammation of the surface of the eye may occur along with dry eye. If left untreated, this condition can lead to pain, ulcers, or scars on the cornea, and some loss of vision and potentially damage to the eye resulting in the loss of the eye.

Cyclosporine (‘Optimmune’), an anti-inflammatory/immunosuppressant medication, is the only prescription drug available to treat dry eye. It decreases corneal damage, increases basic tear production, & reduces symptoms of dry eye. It may take three months of twice-a-day dosages for the medication to work. Often this medication needs to be continued for life to control the problem and unfortunately for some dogs Optimmune treatment doesn't help at all.

In some cases of severe dry eye, short term use of corticosteroid eye drops that decrease inflammation is required. Artificial tears (‘Lacril’, ‘Liquifilm Tears’, ‘Lacri-Lube’) may also be beneficial as a lubricant to the eye & should be applied several times per day ensuring that the timing of Optimmune treatment does not coincide i.e. the Optimmune may be diluted/flushed out of the eye if applied within a similar timeframe to the artificial tears.

Chronic Superficial Keratitis (Pannus)

Chronic Superficial Keratitis (CSK) or Pannus is a condition is which the cornea (the clear dome in front of the eye) becomes inflamed. In many dogs, the third eyelid and part of the conjunctiva (white part of the eye) may also become involved.

Pannus is a progressive, non painful, inflammatory disease.

Pannus

Causes

CSK is immune-mediated, meaning the dog’s immune system, which normally fights infections, acts abnormally and begins attacking / rejecting the corneas.

Both eyes are affected and some dogs also have dry eye problems. As the disease progresses, blindness usually develops.

Treatment

Treatment is the same as for "dry eye" with the addition of steroid eye drops as advised by the vet and after checking the cornea is not ulcerated.