Dry Eye in dogs: Problem, Diagnosis and Treatment

What is dry eye?

Keratoconjunctivitis sicca, or dry eye, is a condition primarily affecting dogs and, as the name states, is a lack of adequate tear production leading to dryness of the eyes. The problem tends to be more prevalent in middle-aged dogs.

The condition usually affects both eyes. Ηowever, the severity of the problem can vary between eyes of the same patient. Tears are produced by the tear gland and the most common reason leading to dry eye is a problem of the dog’s immune system which recognises their tear gland as something “foreign” and attacks it. 

As a result, the tear gland is gradually destroyed and the tear production is reduced over time. Therefore, recognition of the problem early and instigating appropriate treatment is important.

Types of dry eye

Dry eye is the umbrella term used to describe the lack of tears in one or both eyes. The different types of dry eye we see in dogs and cats are associated with:

• Problems of the immune system, leading to dry eye in both eyes in usually middle-aged dogs
• Problems of the nerve system (neurogenic dry eye), leading to dry eye in (usually) one eye
• Reduced tear production associated with complications of certain infectious conditions (i.e., herpes virus in cats)

Signs of dry eye

Common problems seen with dry eye are:

• Purulent, sticky discharge
• Pain and discomfort, usually experienced as squinting of the eye
• Corneal ulcers, which can become sight threatening
• Scarring of the surface of the eye, which can affect vision.

Diagnosis of dry eye

Diagnosis of the condition is based on the use of an absorbent paper strip, called Schirmer Tear Test strip, which measures the amount of tears produced over a period of a minute. This is a test performed by a veterinary surgeon.

Treatment of dry eye

There is a variety of treatments our ophthalmologists will discuss with you. Most of these include ointments, eye drops or combinations of the two to increase your dog’s tear production and to control complications and problems.

It is important to stress that once dry eye has been identified, treatment will be required long-term and should not be discontinued as this will lead to relapse of the problem and risk of complications.

In cases where topical medication is not adequate, surgical options such as drug implants or a procedure called Parotid Duct Transposition can be considered.

Complications of dry eye

Dry eye, when left untreated, can lead to:

• Ongoing pain
• Development of corneal ulcers
• Scarring of the eye
• Impaired vision and eventually loss of an eye.

Prognosis of dry eye

Prognosis depends on the type of dry eye and the stage the disease is diagnosed at. The earlier the problem is diagnosed, the better the prognosis is for long-term preservation of adequate tear production. Therefore, it is important especially in dogs over the age of 5 years, to frequently monitor the tear production as part of their routine health screen. If any concerns are raised, we can review your pet and discuss possible treatments with you during a consultation.