Dry eye in dogs

Overview

• Dry eye is a lack of tears in one or both eyes.
• Dry eye is nearly always ‘immune mediated’, meaning it’s caused by a fault in the immune system, causing it to mistakenly destroy the tear glands.
• Dry eye causes the eyes to become dry, inflamed and very painful.
• It can’t be cured, but can usually be well managed, especially if it’s caught early.
• Contact your vet straight away if you notice your dog has symptoms of dry eye.

What is dry eye?

Dry eye is a lack of tear production. It’s an extremely painful condition that left untreated, can lead to conjunctivitis, eye ulcers, and in severe cases, permanent scarring, or even loss of an eye. In most cases, dry eye in dogs is immune mediated, meaning that the body accidentally destroys its own tear glands. The damage tends to be gradual over a period of months to years, so if the condition is diagnosed and treated early enough, it can usually be well-controlled with medication.

Although most cases of dry eye are immune mediated, some rare cases can be caused by conditions such as hypothyroidism, diabetes, a problem with the nerves that lead to the tear glands (known as ‘neurogenic dry eye’), or as a side effect of certain medicines.

Symptoms

Dry eye tends to develop gradually and cause symptoms that get worse over time. It usually affects both eyes (one eye is often affected first or more severely), and causes symptoms such as: 

• A thick, sticky discharge
• Red, painful, irritated eyes - you may notice your dog closing their eyes more than usual, blinking a lot, or rubbing their face
• Cloudy/dull eyes with a lack of shine
• Frequent eye infections
• Eye ulcers

When to contact your vet

Book an appointment with your vet ASAP if your dog has symptoms of dry eye. Even if your dog doesn’t have the exact symptoms listed above, it’s always best to contact your vet if you are concerned - eyes are too important to leave to chance.

Diagnosis

Your vet can diagnose dry eye based on your dog’s symptoms and by performing a ‘Schirmer Tear Test’ (STT). This is a painless procedure that involves placing a very small strip of paper between your dog’s eyelid and eye. The strip measures the amount of tears each eye is producing, and a normal result is above 15mm/minute (anything below this could indicate dry eye).

Treatment

Dry eye is a condition that usually requires lifelong treatment and regular check-ups. Your dog is likely to need some of the following:  

Medicated eye ointment – Although already damaged tear gland tissue can’t be repaired, immunosuppressant eye ointment can help calm the immune system and prevent any further damage. Ciclosporin is the most commonly used drug and can be very effective – it’s applied twice daily, can take 2-12 weeks to take effect, and if successful needs to be given for life. If ciclosporin doesn’t work, your vet may decide to try a stronger version of it, or a different medication such as tacrolimus. Unfortunately, in advanced cases where the whole gland has already been destroyed, immunosuppressant eye ointment won’t work, so other treatments will need to be considered.

False tears – your dog will need false tears to replace the tears they can’t produce. Initially they will need them very regularly (every 1-2 hours), but once their dry eye is under control, it may be possible to reduce the frequency.

Regular eye wiping - an important part of your dog’s treatment will be keeping their eyes clean and free from infection. Use cotton wool pads soaked in warm water to remove any dried discharge from their eyes at least twice a day. Always hold the pads on your dog’s eyes to wet the discharge to give it a chance to loosen before trying to remove it.  

Surgery - if your dog’s eyes don’t improve with medication, your vet may suggest an operation called a ‘parotid duct transposition’. The aim of this surgery is to surgically move one of the tubes that carries saliva into the mouth and redirect it into the eye. This means that saliva keeps the eye moist instead of tears – which can be very effective. In some dogs, saliva can be irritating to the surface of the eye or may cause skin irritation under the eye, so for this reason, parotid duct transpositions are usually a last resort.

Enucleation - if your dog has severe dry eye that is unresponsive to treatment, or is causing a lot of pain, it may be necessary to consider enucleation (eye removal). If you are considering this, speak to your vet for advice about their quality of life, and caring for a blind dog.

Other

• Antibiotic eye drops aren’t a standard part of treating dry eye, but may be needed from time to time if your dog develops an eye infection because of their condition. If your vet gives your dog antibiotic eye drops it’s very important to follow the instructions and complete the course. This will make sure the infection is fully treated and doesn’t return.
• A buster collar may be necessary to stop your dog from rubbing their eyes while their medication takes effect.

Outlook

If your dog’s dry eye is spotted and treated before their entire tear gland is destroyed, they are likely to respond well and stay under control for many years. If medication is unsuccessful, you will need to consider options such as a parotid duct transposition or even enucleation (surgery to remove their eyes).

Most dogs with symptoms severe enough to warrant enucleation are already blind, so cope well without their eyes, and go on to live happy, pain free lives. If your dog’s dry eye is causing them a lot of pain, and there are no other treatment options available you may need to consider putting your dog to sleep to stop them suffering.

Breeds prone to dry eye

Most cases of dry eye are inherited (passed from parent to puppy), which is why it’s particularly common in certain breeds such as:

• Cavalier King Charles Spaniel
• Pug
• West Highland White Terrier
• Yorkshire Terrier
• Shih Tzu

Prevention

We strongly recommend against breeding from a dog that has been diagnosed with dry eye, even if their condition is well controlled. In addition to this, if you are considering getting a dog it is important to research any potential health problems in the breed you are considering (including dry eye).

Cost

Dry eye can become very expensive to treat, especially because it usually requires lifelong treatment. It’s important to speak openly to your vet about your finances, the cost of treatment, as well as what you think is right for your dog. If one treatment option doesn’t work for you and your pet then your vet may be able to offer another.

Always consider insuring your dog as soon as you get them, before any signs of illness start. This will ensure you have all the support you need to care for them.

FAQs

Published: July 2023

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