Does your pet have sore, red or sticky eyes with a mucus discharge? These are all signs of a problem which may have a number of underlying causes. Common causes include conjunctivitis, allergies or scratches to the surface of the eye, but for some dogs the underlying reason may be a problem with a lack of tear production resulting in ‘dry eye’.
So why are tears important? Tears carry oxygen and nutrients to the cornea (the clear outer part of the eye), lubricate and cleanse the eyes and help to protect against infection. Tears play an important role in keeping your pet’s eyes healthy.
Dry eye is characterised by a reduced or total lack of tear production and is most commonly caused by destruction of the tear glands by the dog’s own immune system. Recent figures indicate that as many as 1:22 dogs may be affected.
If left untreated, the eyes gradually become more and more inflamed and painful as they are unable to cleanse and lubricate properly with insufficient tears. However, the appearance of the condition can be quite varied with some pets’ eyes appearing relatively normal despite little or no measurable tear production.
Happily there is a simple test that can be performed by your vet to check tear production. This is called the Schirmer Tear Test and involves holding a sterile paper test strip in the corner of your dog’s eye for one minute and measuring how far the dye in the paper travels in that time. The greater the measurable distance the greater the tear production and the less the chance of ‘dry eye’.
Better still, medication for ‘dry eye’, usually in the form of an ointment, can improve tear production and reverse many of the signs of ‘dry eye’, maintaining vision and keeping pets comfortable. If your pet shows any of these symptoms you should let your vet know sooner rather than later the earlier the problem can be diagnosed and treatment started the better the long term outlook for affected pets.
Chris Devlin BVSc MRCVS is a Vet and Partner at Hillside Veterinary Centre in Corfe Mullen. w: www.hillsidevets.co.uk.