Dry Eye in Dogs – A common but treatable condition

Dry eye or keratoconjunctivitis sicca (KCS) is a common disease in dogs where there are insufficient or poor quality tears. Tears are required to lubricate and cleanse the eye as well as protect against infection and damage to the cornea (the surface of the eye). If there is a disruption to the production of tears to one or both eyes then this can result in corneal ulceration or recurrent infections and may even cause blindness. 

This disease affects approximately 5% of dogs so it is really important that owners are aware of the signs to look out for and get it treated promptly so that irreversible damage does not occur.

What is the cause of dry eye in dogs?

Dry eye is caused by the body’s own immune system attacking the tear producing glands, leading to a reduction of natural tears being released. Without enough tears the eyes become dry and uncomfortable for the dog. 

What are the signs of dry eye?

The signs of dry eye are quite variable and can occur in one or both eyes:

  • White or yellow discharge from the eyes
  • Eyes are red or inflamed
  • Recurrent conjunctivitis (infection)
  • Corneal ulceration (damage to the surface of the eye)
  • Blood vessels or a dark pigmentation accumulating on the surface of the eye
  • Eye irritation (squinting, excessive blinking or rubbing at the eyes)
  • Blindness 

Only one or two of the signs listed above may be present in the early stages of the disease.

How is dry eye diagnosed? 

If you suspect your pet may have dry eye, it is important to organise a veterinary consultation for a Schirmer tear test to be performed. This involves putting a small absorbent strip of paper into the corner of each eye for 30-60 seconds to measure the tear production for your dog. Most dogs tolerate this very well without any sedation or much restraint. A reading of <15mm of tear production is considered abnormal.

Are some dog breeds more susceptible to dry eye? 

Any dog breed can be affected by dry eye but there are some breeds that are more susceptible to the disease including:

  • Cocker Spaniel
  • West Highland White Terrier
  • Cavalier King Charles Spaniel
  • Shih-Tzu
  • Yorkshire Terrier
  • Bulldog
  • Pug
  • Pekingese
  • Lhasa Apso 

These breeds should have a Schirmer tear test performed more regularly to check the tear production is normal, for example at the annual health examination

What is the treatment for dry eye ?

Lubricating the eyes is only masking the problem and not treating the underlying issue, which is the immune system’s attack on the tear glands. Even if your pet’s eyes look normal, if the tear production is reduced it will only get worse over time, potentially leading to blindness. 

We need to medicate the eyes with a special eye ointment which stops the immune system from attacking the tear glands. The drug that has been found to be most effective is cyclosporine ointment registered for use in dogs called Optimmune (contains 0.2% cyclosporine).

Treatment is started using just a tiny amount (equal to the size of a grain of rice) in the affected eye(s) twice daily then the Schirmer tear test is repeated 2-4 weeks later to check the progress. If successful, once the tear production normalises, the frequency of treatment with the ointment can be eventually reduced to alternate days. This is determined on a case by case basis by your vet.

It is important to clean the eyes first with saline soaked cotton balls to remove any accumulated debris and mucus from inside and around the eyes. Your vet may also prescribe an antibiotic and/or a lubricant in the interim until any infection clears and the tear production improves. 

When the tear production is normal again, how often should I have my dog’s eyes checked?

In the initial stages of treatment, eye examinations should be fortnightly, then monthly, then 3 monthly. Once the condition has stabilised and is responding to the medication, a vet check up including a Schirmer tear test should be performed at least every 6 months, particularly as your pet is on a prescription medication and needs careful monitoring.

What if my dog does not respond to the cyclosporine treatment? 

If treatment with cyclosporine is unsuccessful, your vet may recommend a referral to a veterinary ophthalmologist (vet eye specialist) to reassess the problem and find an alternative treatment. Another drug called tacrolimus is sometimes prescribed but it is important to have the eyes examined thoroughly in case there is a concurrent problem with the eye(s).

The main thing to remember is if your dog has reduced tear production, treatment with cyclosporine as soon as possible is recommended to prevent further destruction of the tear glands which may cause irreversible blindness in your pet.