The technical name for hay fever is allergic rhinitis, when the lining of the nose and eyes become inflamed after exposure to allergens (typically pollens). Around one in five people are affected in the UK, sneezing, and suffering from runny eyes, especially during periods of high pollen counts in the summer.
While allergies are common in dogs, the specific manifestation of solely upper respiratory signs (i.e. “hay fever”) is rare. Generalised skin disease caused by pollen allergy (known as atopy) is far more common. While dogs suffering from allergies may have some sneezing and snuffling as part of the overall picture, these signs are usually minor compared to the severely itchy skin.
For those rare cases where pollen allergy does provoke significant sneezing and runny eyes in dogs, simple therapies that help humans such as anti-histamine tablets are unlikely to help dogs: topical anti-inflammatory eye and nose drops supplied by the vet are far more effective.
If my dog doesn’t have hay fever, why are his eyes streaming?
There are many other causes of streaming eyes in a dog, and the sign should never be ignored: this indicates that your dog’s eyes are likely to be uncomfortable, and veterinary attention should be sought.
Common causes include ocular foreign bodies (such as grass seeds), scratches and ulcers on the surface of the eyeball, and one common hidden illness that’s poorly recognised by owners. Nearly half (46%) of dog owners are not aware that dogs can suffer from Dry Eye, or Keratoconjunctivitis Sicca (KCS).
What is Dry Eye and how is it diagnosed?
Dry Eye is a condition where insufficient tears are produced by the tear glands. It is usually due to the auto-immune destruction of a dog’s tear glands, by the dog’s own immune system. The tear glands are then unable to produce the normal amount of tears, causing the surface of the eye to dry out. It seems paradoxical that a dog with dry eyes should have tears streaming down the face: this is a result of the irritation caused by the dryness. Have you ever put your head outside of a speeding car, staring into the wind? If so, you’ll remember the way your eyes began to hurt as they dried out, and you’ll remember how your face felt wet as if you’d been crying when your brought your head back in. That’s exactly what happens to dogs with Dry Eye, except the dryness carries on for weeks and months, not just for a few minutes. The condition leads to severe discomfort and, if left untreated can progress to have very serious consequences, including scarring and even blindness.
What is the risk of a dog getting Dry Eye?
Some breeds are predisposed to Dry Eye, with as many as one in five dogs being affected: examples include Pugs, Cocker Spaniels, West Highland White Terriers and Cavalier King Charles Spaniels. Owners of these breeds in particular should be aware of the signs of the problem, as early treatment is the best approach.
What are the signs of Dry Eye
Dry Eye symptoms vary, but the most obvious signs are usually:
- A discharge streaming from one or both eyes
- Repeated episodes of conjunctivitis or ulcers
- Signs of discomfort in the eye, with redness, excessive blinking or rubbing
- A dry or dull appearance to the surface of the eye
How is Dry Eye diagnosed?
Your vet can perform a simple test in just a few minutes to detect if your dog has Dry Eye. The test involves placing a small strip of filter paper (5mm by 25mm) into the lower part of the eye, and measuring the quantity of tears produced in one minute. A “normal” level is around 15mm of tear flow; severe cases may has zero measurable tear production. If your dog is one of the predisposed breeds, it can be worth asking your vet to check this measurement routinely at the annual health check.
How is Dry Eye treated?
Dry Eye in dogs can be treated in one of three main ways.
- An immunosuppressant drop can be applied daily: this stops the body’s immune system from attacking the tear glands, allowing normal tear production to resume.
- Artificial tears can be applied regularly to the dog’s eyes: this provides artificial lubrication to the surface of the eye, relieving the discomfort and inflammation.
- A surgical operation is possible, redirecting saliva from the dog’s oral cavity to the lining of the eye. A low flow of saliva provides effective lubrication, with a downside being that whenever the dog sees food, there’s copious “tear” production caused by the reflex increased saliva production. If a dog cries when it sees food, now you know a possible reason.
Can Dry Eye be completely cured?
Dry Eye in dogs usually requires lifelong treatment, but if this is given, most dogs suffer from no signs of the illness. If treatment is not given, serious consequences are likely, but these are easily avoided by working closely with your vet.
What about about other causes of streaming eyes and sneezing in dogs?
The eyes and nose are sensitive structures: if any animal has signs that would make an owner want to see the doctor, the pet should be taken to the vet. A precise diagnosis of the issue is the key: appropriate treatment can then be given.
What about Dry Eye in cats?
I’ve never diagnosed Dry Eye in cats as a vet in general practice: although it does occur, there are many other, far more common causes of streaming eyes. As with dogs, it’s a sign that should never be ignored: it’s unlikely to go away on its own, and if left untreated, serious, long term consequences are likely.