In 2024 a team of veterinary eye specialists published the records of 500 Shih Tzus they had examined, a thousand eyes in all. Only 36 of those eyes were completely normal. The other 964, more than 96 per cent, had at least one finding. That sounds alarming, and it is worth knowing, but most of what they found is mild, visible to an owner who knows where to look, and manageable. This guide goes through what the study found, what each problem looks like at home, and which signs mean a vet the same day.
Why the Shih Tzu eye is different
The breed’s short face and shallow eye sockets push the eyes forward. A prominent eye is exposed to more air, more dust and more hair, it can be harder for the lids to close fully over it, and the folds of skin and hair around it sit closer to its surface. Almost every finding in the study comes back to that shape.
What the 1,000-eye study found
The three most common findings, which between them affected about half of all the eyes examined (Rajaei and colleagues, Veterinary Ophthalmology, 2024):
- Hair growing from the inner corner of the eye, about 21% of eyes. The little pink lump in the inner corner, the caruncle, can grow fine hairs that touch the surface of the eye. What you see: a wet inner corner, tear staining, the eye looking a little irritated.
- Tears that break up too fast, about 18%. The tear film should coat the eye evenly between blinks. In these eyes it breaks apart early, leaving dry patches. What you see: often nothing, sometimes a dull look, more blinking, or recurring redness.
- The inner part of the lower lid rolling inwards, about 10%. The lid margin and its hair turn towards the eye in the inner corner. What you see: constant watering and staining on that side.
The authors also list dry eye, brown pigment spreading over the clear front of the eye, eyelids that do not close fully, and mature cataracts among the most common problems.
A smaller study from the Hebrew University’s veterinary school, which examined 50 Shih Tzus in detail in 2023, makes the same point more starkly: the lids did not close completely when the dog blinked in 82% of eyes, and every eye examined had hair at the inner corner and some inward roll of the lower lid there. In other words, these features are close to normal for the breed. The question for an owner is not whether their Shih Tzu has them, but whether they are causing trouble.
The conditions, one at a time
Eyelids that do not fully close. If you watch your Shih Tzu sleep and see a sliver of eye showing, that is it. The exposed strip dries out and is where ulcers and pigment tend to start. Mention it to your vet; some dogs need lubricating drops, and severe cases can have the eyelid opening narrowed surgically.
Dry eye. The eye makes too few tears. It starts with a sticky, stringy discharge and a dull surface, and over time the eye turns red and brown. Vets diagnose it with a simple paper strip test that measures tear production in a minute. It is very treatable with daily drops, but it does not go away on its own, and untreated it can cost the dog its sight.
Pigment on the eye. Brown pigment creeping across the clear front of the eye, usually from the inner corner, is the eye’s response to long-term irritation, dryness or rubbing. It is not itself painful, but it is a sign that something has been bothering the eye for a while, and in advanced cases it blocks vision. Treating the cause can stop it spreading.
Cataracts. A cloudy or white lens behind the pupil. Mild bluish haze in older dogs is often a normal ageing change rather than a cataract, so let the vet tell the two apart.
Corneal ulcers. A scratch or erosion on the surface of the eye. In UK vet records ulcers were more common in Shih Tzus than in dogs overall, as our Shih Tzu health guide sets out. A prominent eye that does not fully close and a dry tear film make a Shih Tzu easier to injure and slower to heal.
What you can actually do at home
- Keep hair off the eyes. A topknot, or a short trim on the nose fold and the inner corners, takes away the most common irritant in the study. It is also the single best thing for tear staining.
- Wipe the corners once a day. A soft pad, damp with clean water or an eye-safe solution, from the inner corner outwards and away from the eye, a fresh pad for each eye. Our tear stain guide covers the routine in detail.
- Look properly, in good light, once a day. Both eyes should look the same: same size, equally open, clear, shiny, no cloudy patches, no new brown areas.
- Watch the sleeping dog. Once in a while, check whether the lids close fully.
- Ask for a tear test. At the annual check-up, ask the vet to measure tear production, especially from middle age on. Catching dry eye early makes it much easier to manage.
- Be careful with anything near the face. Play with other dogs and cats, brambles, and grooming scissors near the eyes are the usual causes of injury. Round-tipped scissors and a steady dog are the minimum for trimming there.
When to see a vet the same day
- Squinting, holding an eye shut, or pawing at the face
- A cloudy, blue or white patch on the eye that was not there yesterday
- One eye looking bigger, redder or more bulging than the other
- Thick yellow or green discharge
- An eye that has come forward out of its socket, which can happen to short-faced breeds after a knock or even rough handling. Cover it with a clean wet cloth and go straight to an emergency vet.
Eye problems change fast. An ulcer that is a small scratch in the morning can be a deep one by the next day, so with eyes, waiting to see is the wrong instinct. Do not put human eye drops or leftover drops from a previous problem into the eye without asking; some of them make ulcers worse.