Eye disease is one of the health conditions that dogs owners should know about, because it affects quality of life, and it is easier to manage when it is caught early. This guide explains what eye disease is, the signs to watch for, what causes it, how it is diagnosed, how it is treated, whether it can be prevented, and how to live with a dog that has it. Every suggestion here is general guidance, not a prescription for an individual dog.
Shih Tzus are the focus of this guide. A typical adult Shih Tzu weighs 4–7 kg, with a typical lifespan of 10–18 years, and is commonly described as affectionate, playful, lively. Shih Tzus are prone to eye problems, and eye issues are listed as a common health issue for the breed on this site. Their eyes stick out, which makes them easy to injure, and their eyelids and tear ducts are often a problem. The rest of this guide covers the condition itself — what it is, the signs, the causes, how it is diagnosed, how it is treated, and how to live with it — with the breed in mind throughout.
What is eye disease in dogs?
Eye disease is a condition where the eyes or the structures around them become damaged or diseased — from cataracts, where the lens goes cloudy, to glaucoma, where the pressure inside the eye rises, to infections, injuries, and problems with the eyelids and tear ducts. Eye disease can affect one eye or both, and it can come on slowly or suddenly. A dog with eye disease may lose its sight, partly or fully, and it may be in pain — which is why any change in the eyes should be checked by a vet promptly, not watched and waited on.
The rest of this guide covers the signs, the causes, how eye disease is diagnosed, how it is treated, whether it can be prevented, and how to live with a dog that has it. A dog with eye disease should be checked by a vet, because the right treatment depends on the individual dog, its age, and how advanced the condition is — and because some of the signs of eye disease can also be signs of other conditions, which need a vet to tell apart. The dog ideal weight calculator works out a target weight range, and the when is a dog considered a senior guide gives the senior thresholds by size.
Signs of eye disease in dogs
The signs of eye disease in dogs are listed below. Not every dog with eye disease will show every sign, and some dogs will show only one or two — but any one of these signs, especially if it lasts more than a few days or gets worse, is worth mentioning to a vet. A dog that is bright, eating, drinking, and otherwise well between episodes is less likely to be seriously ill than a dog that is lethargic, off its food, or losing weight — but the only way to know is to check.
- Cloudiness in the eye, or a white or blue haze over the lens.
- Redness in the whites of the eyes, or in the eyelids.
- Squinting, blinking, or holding an eye closed.
- Discharge from the eyes, or tears that run down the face.
- Bumping into things, hesitating in the dark, or being startled more easily.
- A dog that paws at its eyes, or rubs its face on furniture.
- A change in the size of the pupils, or pupils that do not react to light.
If two or more of those signs apply, or if one sign is severe — a dog that cannot urinate, cannot breathe, cannot stand, or has had a seizure lasting more than five minutes — see a vet the same day. Those are signs that need a vet, not waiting. Bring a note of when the signs started, how often they happen, and what the dog eats and drinks — that information helps the vet far more than a guess about the cause. The how to tell if your dog is overweight guide gives the hands-on check for weight, which matters for many of these conditions.
Causes and risk factors for eye disease
Eye disease has many causes, and they differ by the condition. Cataracts are often linked to age or to diabetes, and they are more common in some breeds. Glaucoma is often inherited, and it is more common in some breeds. Infections can be caused by bacteria, viruses, or other germs. Injuries can be caused by a scratch, a knock, or a foreign body in the eye. Some breeds are more prone to eye problems because of their build — flat-faced breeds, for example, have eyes that stick out and are easily injured, and some breeds have eyelids that roll in or out. Age is the biggest risk factor for cataracts.
Some dogs are more prone to eye disease than others, because of their genes, their breed, their size, or their age — but breed and age are not destiny, and a dog of any breed can develop eye disease. What an owner can control is weight, food, exercise, and vet checks: a dog at a healthy weight, with measured food and daily exercise, is less likely to develop eye disease and will cope better with it if it does. A dog that is overweight, that eats a poor diet, or that never sees a vet is more likely to develop eye disease and to have it found late, when it is harder to treat.
How eye disease is diagnosed
A vet diagnoses eye disease by examining the eyes with a light and a magnifier, and by testing the pressure inside the eye, the tear production, and the dog's vision. The vet may also use a dye to check for a scratch on the surface of the eye, and may refer the dog to a veterinary eye specialist for further tests. A dog with a cloudy eye, a red eye, a squinting eye, or a sudden change in vision should be seen by a vet promptly — some eye conditions, such as glaucoma, can cause blindness within hours if they are not treated.
If you are worried about your dog, see a vet and mention eye disease by name, with the signs you have seen and when they started. Bring a note of what the dog eats, how much, and any medicines it takes, and whether it has had eye disease or a related condition before. A video of the signs, if it is safe to take one, helps the vet far more than a description — especially for seizures, limping, or breathing problems. Do not try to diagnose eye disease yourself, and do not buy medicines or special diets for it without veterinary advice, because the wrong treatment can make it worse.
Treatment and management of eye disease
Treatment depends on the condition: an infection needs drops or ointment, a scratch needs drops and rest, cataracts may need surgery, and glaucoma needs drops to bring the pressure down — urgently, because high pressure can blind an eye within hours. Some eye conditions need lifelong drops, and some need surgery. Do not put anything in a dog's eye without veterinary advice, and do not use drops meant for people — some of them are dangerous for dogs. A dog that has lost its sight can still live a full and happy life, as long as its home stays the same and it is not moved around.
Treatment is a decision made with the vet, weighing the dog's age, health, and quality of life against the treatment and its side effects. Some owners choose not to treat, and to keep the dog comfortable instead — and that is a valid choice, made with the vet, not on the basis of a web page. Whatever is decided, the treatment must be followed every day, at the same times, and the dog must be checked regularly, because eye disease changes over time, and the treatment needs to change with it. Do not stop a medicine suddenly, and do not change the dose without veterinary advice.
Living with a dog with eye disease
A dog with eye disease can live a full and happy life with the right care, but it needs a routine: drops or medicines as the vet advises, regular vet checks, and a home that stays the same — furniture in the same place, food and water in the same place, and no sudden changes. A dog that has lost its sight will learn its home by smell and memory, and it will cope well as long as nothing moves. Mention any change to the vet promptly — a cloudy eye, a red eye, or a dog that is bumping into things needs a vet visit, not waiting.
Keep a routine: the same times for food, medicines, walks, and play, the same places for furniture, food, and water, and a calm, predictable home. Keep a note of appetite, drinking, weight, and behaviour, and mention any change to the vet promptly — a change that lasts more than a few days, or that gets worse, is worth a vet visit. Keep the dog at a healthy weight, with measured food and daily exercise at a level that suits its body, and keep vet checks regular: once a year as an adult, and twice a year as a senior. The senior dog diet guide covers feeding older dogs, and the dog calorie calculator works out daily calories for any weight.
Why Shih Tzus are prone to eye disease
Shih Tzus are prone to eye problems, and eye issues are listed as a common health issue for the breed on this site. Their eyes stick out, which makes them easy to injure, and their eyelids and tear ducts are often a problem. That does not mean every Shih Tzu will develop eye disease — it means owners of the breed should know the signs, and mention them to the vet early, because eye disease is easier to manage when it is caught early. A Shih Tzu that is kept at a healthy weight, with measured food and daily exercise, is less likely to develop eye disease and will cope better with it if it does.
Can eye disease be prevented?
Eye disease cannot always be prevented, because much of it is about age and genes — but the risk can be reduced. Keep the dog's eyes clean, and wipe away discharge with a clean, damp cloth. Keep the dog away from things that can scratch its eyes, and do not let it stick its head out of a car window. If you are buying a puppy of a breed that is prone to eye problems, ask what eye screening the parents had. Have the vet check the eyes at every routine visit, so a problem is found early, when it is easier to treat.
Early checks matter most: have the dog checked regularly, so eye disease is found early, when treatment works best. Keep the dog at a healthy weight, with measured food and daily exercise, and mention any change in drinking, eating, weight, or behaviour to your vet early, because a change caught early is easier to treat than one left for weeks.
For related reading, see the Shih Tzu food guide, the Shih Tzu lifespan guide, the dog ideal weight calculator, the dog body condition score chart, the how to tell if your dog is overweight guide, the senior dog diet guide, the dog calorie calculator, the when is a dog considered a senior guide.
Frequently asked questions
What is eye disease in dogs?
Eye disease is a condition where the eyes or the structures around them become damaged or diseased — from cataracts, where the lens goes cloudy, to glaucoma, where the pressure inside the eye rises, to infections, injuries, and problems with the eyelids and tear ducts. Eye disease can affect one eye or both, and it can come on slowly or suddenly. A dog with eye disease may lose its sight, partly or fully, and it may be in pain — which is why any change in the eyes should be checked by a vet promptly, not watched and waited on.
What are the signs of eye disease in dogs?
The most common signs are: Cloudiness in the eye, or a white or blue haze over the lens. Redness in the whites of the eyes, or in the eyelids. Squinting, blinking, or holding an eye closed. See the full list above for every sign to watch for, and see a vet promptly if two or more apply, or if one sign is severe.
What causes eye disease in dogs?
Eye disease has many causes, and they differ by the condition. Cataracts are often linked to age or to diabetes, and they are more common in some breeds. Glaucoma is often inherited, and it is more common in some breeds. Infections can be caused by bacteria, viruses, or other germs. Injuries can be caused by a scratch, a knock, or a foreign body in the eye. Some breeds are more prone to eye problems because of their build — flat-faced breeds, for example, have eyes that stick out and are easily injured, and some breeds have eyelids that roll in or out. Age is the biggest risk factor for cataracts.
How is eye disease diagnosed?
A vet diagnoses eye disease by examining the eyes with a light and a magnifier, and by testing the pressure inside the eye, the tear production, and the dog's vision. The vet may also use a dye to check for a scratch on the surface of the eye, and may refer the dog to a veterinary eye specialist for further tests. A dog with a cloudy eye, a red eye, a squinting eye, or a sudden change in vision should be seen by a vet promptly — some eye conditions, such as glaucoma, can cause blindness within hours if they are not treated.
How is eye disease treated?
Treatment depends on the condition: an infection needs drops or ointment, a scratch needs drops and rest, cataracts may need surgery, and glaucoma needs drops to bring the pressure down — urgently, because high pressure can blind an eye within hours. Some eye conditions need lifelong drops, and some need surgery. Do not put anything in a dog's eye without veterinary advice, and do not use drops meant for people — some of them are dangerous for dogs. A dog that has lost its sight can still live a full and happy life, as long as its home stays the same and it is not moved around.
When should a dog with eye disease see a vet?
See a vet promptly if the dog shows any of the signs above, especially if they last more than a few days or get worse — and the same day if the dog cannot urinate, cannot breathe, cannot stand, has had a seizure lasting more than five minutes, or is lethargic or off its food. Bring a note of when the signs started and what the dog eats and drinks. A dog with eye disease should be checked by a vet, because the right treatment depends on the individual dog, its age, and how advanced the condition is.
Results on this page are estimates for general information only and are not veterinary advice. If your pet is ill, underweight, overweight, pregnant, or has a health condition, consult your veterinarian before changing diet or care.