Case File

Evie is a 10-year-old Jack Russel Terrier who came to me because her left eye was red and cloudy, and she was squinting. Her tail was still wagging of course!

I started my examination by visually assessing the eye. The outermost surface of her eye, known as the cornea, had fluid accumulating within it. We call this corneal oedema and it makes the eye look blue. There were also new blood vessels extending over the cornea indicating repair. Evie wasn't able to hold her eye open, which suggested ocular pain, and the left side of her nose was dry and crusty.

Before I applied any drops, I measured how much tear each eye was able to produce. I did this by using a special paper strip which was placed against the cornea, which should therefore stimulate tear production. The good eye produced a normal number of tears, however her left eye did not produce any tears at all. This indicates insufficient tear production and we call this keratoconjunctivitis sicca, commonly known as 'dry eye'. This diagnosis could explain the signs she originally came in for.

Dry eye is a common condition in dogs and can have numerous causes. The most common is due to an abnormal immune response by the body, and other causes include nerve damage, drugs and hormonal conditions.

The nerve that stimulates the eye to produce tears also targets the glands in the nose. Therefore, given that the left side of her nose was also dry, I suspected the cause of Evie's dry eye was due to a nerve being damaged. On this assumption, Evie's owner was given lubricating eye drops to apply 4-5 times daily, and a specific medication to go on her food. This medication stimulates the eye glands to produce tears. It is important to closely monitor for side effects of the medication, therefore I spoke with Evie's owner regularly and booked re-examinations to check her tear production.

In some cases the condition will resolve following a few months of treatment. Fortunately, Evie started to produce tears in her eye and the other signs she originally came in for (red eye, corneal oedema, squinting) resolved. Following several months of treatment we stopped the nerve-specific medication and she can now produce her tears in that eye again!