Pug Eye Problems: What a 294-Dog German Study Found—and What It Cannot Predict

Pugs have a face people fall in love with instantly.

Those same big eyes, shallow eye sockets, short muzzle, and facial folds can also create a crowded piece of anatomy where eyelids, hairs, tear film, cornea, and exposed eye surface all have to get along. Sometimes they do. Sometimes they really do not.

A 2026 study in Veterinary Ophthalmology gives pug owners a useful look at how often several presumed inherited eye disorders appeared in a screened German pug population.

The numbers are attention-grabbing. They are also very easy to misuse.

The study does not tell you that your pug has a 72% chance of developing entropion, or that every German pug has an eye problem, or that you can diagnose one of these conditions by staring at a photo online.

What it does give us is a well-documented snapshot of 294 pugs examined through the German panel of the European Eye Scheme—and a strong reason to take pug eye health seriously without turning a population study into a diagnosis.

What the researchers actually studied

Researchers retrospectively analyzed standardized eye-examination records from 294 pugs in Germany.

The examinations were performed between June 2013 and March 2023 by veterinarians certified as European Eye Scheme Examiners or by specialists holding European veterinary ophthalmology credentials.

The researchers were looking for known and presumed inherited eye diseases and for possible associations with age and sex.

That matters because this was not a random sample of every pug living in Germany.

These were dogs that had undergone formal eye examinations within a screening system. Some were examined for breeding purposes and others were not.

So when you see a percentage in this study, read it as:

> “Among these 294 screened pugs in this German dataset…”

not:

> “This is the exact probability for my pug.”

That distinction is the whole article.

The most common findings

The study reported the following diagnoses most often:

• Entropion: 72.4%
• Pigmentary keratopathy: 36.7%
• Macroblepharon: 24.8%
• Distichiasis: 20.1%
• Non-congenital hereditary cataract: 12.2%

Looking at broader anatomical groups, the researchers reported that 81.3% of the pugs had at least one disorder involving the ocular adnexa—the structures around the eye, such as the eyelids—and 41.5% had at least one corneal disorder.

Those are high numbers.

They are not universal pug prevalence estimates.

The study authors explicitly caution that the screened population may overrepresent or underrepresent some conditions because only dogs examined within this specialist screening system were included.

What do those terms mean?

You do not need to become a veterinary ophthalmologist to understand why these findings matter.

Entropion

Entropion means part of the eyelid rolls inward, allowing hair or skin to rub against the eye surface.

The study found entropion more often than any other listed diagnosis.

For an owner, the important point is not learning to diagnose entropion yourself. It is understanding that eyelid shape can contribute to chronic eye irritation in pugs and deserves proper veterinary examination.

Pigmentary keratopathy

Pigmentary keratopathy involves pigment developing on the cornea.

The study reported it in more than one-third of the screened pugs.

The authors discuss several possible contributing factors that can irritate the eye surface, including eyelid abnormalities, facial hairs, tear-film problems, and other conformational features.

Again, a dark area on an eye is not something to identify from an internet checklist. It is something a veterinarian should examine.

Macroblepharon

Macroblepharon refers to an unusually large eyelid opening.

In a flat-faced dog whose eyes may already be relatively prominent, eyelid opening and eye exposure can matter.

The study reported macroblepharon in about one-quarter of the screened dogs.

Distichiasis

Distichiasis occurs when extra eyelashes grow from the eyelid margin in a position where they can contact the eye.

Some affected dogs may show obvious irritation. Others may not.

The study reported distichiasis in about one-fifth of the pugs.

Hereditary cataract

The study also recorded non-congenital hereditary cataract.

Cataracts involve opacity within the lens, but the study's 12.2% figure should not be treated as a general prediction for every pug. The authors note that their population was mainly young and middle-aged, which could actually underestimate some age-related disorders.

Age mattered for some findings

The researchers found that increasing age was associated with a higher probability of:

• pigmentary keratopathy;
• keratoconjunctivitis sicca, often called dry eye; and
• hereditary cataract.

They did not find a significant association with sex for the selected diseases they analyzed.

That does not mean every older pug will develop those conditions. It means age was associated with higher probability within this dataset.

Why the percentages are not a personal risk calculator

This is where a useful study can become a bad social-media post.

The authors list several limitations.

1. It was retrospective

The researchers analyzed records that already existed rather than prospectively enrolling a random group of pugs and following them under one new protocol.

Retrospective research can identify important patterns, but it is more vulnerable to certain biases.

2. The dogs were a selected screened population

Only pugs examined by European Eye Scheme Examiners or veterinary ophthalmology specialists were included.

Owners who pursue formal eye screening may differ from the general population of pug owners. Breeding dogs may differ from pets that never enter a screening program.

The authors specifically say some conditions may therefore be overrepresented or underrepresented.

3. Some uncertain diagnoses were coded as unaffected

For statistical analysis, records marked suspicious or undetermined were treated as unaffected.

That could lead to underestimation of some disease prevalence.

4. The records span about ten years

Breeding choices, conformation, owner awareness, and screening interpretation can change over a decade.

The authors note that changes in the screening scheme itself could also influence how abnormalities were recorded.

5. The population skewed young to middle-aged

That could underestimate disorders that become more common later in life.

So the percentages are valuable research numbers. They are not a calculator where you type in “pug, age six” and receive a diagnosis.

What should a pug owner actually do with this information?

You do not need to memorize five prevalence percentages.

A much more useful takeaway is that routine eye attention matters in a breed whose anatomy can put the eye surface at extra risk.

Know what is normal for your pug

Look at your dog's eyes when they are comfortable and acting normally.

That gives you a baseline for:

• how open the eyes usually are;
• normal tear or discharge level;
• normal eye color;
• whether one eye normally looks different from the other; and
• how your pug normally reacts to light and touch around the face.

You are not performing an exam. You are learning your dog's normal.

Treat new eye discomfort as worth a call

If your pug suddenly starts squinting, pawing at an eye, holding an eye closed, producing unusual discharge, or showing a visible change in the eye, do not try to match the symptom to one of the percentages above.

Call your veterinarian.

Eye problems can look similar from the outside while requiring very different treatment.

Do not use leftover eye medication

A medication prescribed for one eye problem—or for another dog—may be wrong for a different condition.

The study is a good reminder that multiple eyelid, corneal, and tear-film problems can occur in the same breed and sometimes together.

Diagnosis comes before treatment.

Ask about the eyelids, cornea, tear film, and eye exposure

At a routine veterinary visit, especially if your pug has recurring eye irritation, it is reasonable to ask:

• Do the eyelids sit normally against the eye?
• Are hairs or folds contacting the cornea?
• Is the tear film adequate?
• Is there corneal pigmentation or scarring that should be monitored?
• Does the eye appear unusually exposed?
• Would a veterinary ophthalmology referral add useful information?

Those are questions, not a home exam.

If you are considering breeding, formal screening matters

The study was built from formal European Eye Scheme examinations, and the authors argue that ophthalmic screening can help characterize presumed inherited eye disease and improve ocular welfare.

Breeding decisions are not simply about whether a dog “looks fine.”

A normal-looking eye in the kitchen is not the same thing as a standardized veterinary ophthalmic examination.

What if your pug has never had an eye problem?

Good.

This study is not a prediction that one is coming.

Population research tells us where a breed may carry increased burden. It does not override the actual health of the individual animal.

The right response to breed-risk research is not anxiety. It is appropriate awareness.

Your pug is not a percentage.

What if your pug already has one of these diagnoses?

This article cannot tell you what treatment your dog needs.

Conditions such as entropion, pigmentary keratopathy, dry eye, distichiasis, or cataract can vary in severity and cause.

A veterinarian—and sometimes a veterinary ophthalmologist—can evaluate the specific eye, the dog's comfort, vision, tear production, eyelid anatomy, and other findings.

Use the study as background, not as a substitute for that exam.

The bigger welfare point

One of the study's conclusions is hard to separate from pug anatomy.

The authors say the high burden of eyelid-region and corneal disorders likely reflects, directly or indirectly, the breed's exaggerated facial conformation.

That does not make loving a pug a moral failure.

It does make health-oriented breeding, screening, and less extreme conformation worth discussing seriously.

The personality people adore does not come from an eyelid rolling inward.

The comic timing does not require an irritated cornea.

The stubborn little shadow following you into the bathroom is still a pug if we care more about comfortable eyes.

Bottom line

The 2026 German study found a high prevalence of several presumed inherited eye disorders in a screened population of 294 pugs.

The most common recorded diagnoses were entropion, pigmentary keratopathy, macroblepharon, distichiasis, and hereditary cataract.

Those findings are useful.

The percentages are not a universal prediction for every pug, because the study was retrospective, involved a selected screening population, covered a decade of records, and had other limitations the authors clearly acknowledge.

For owners, the practical message is simpler:

Know your pug's normal eyes. Take new eye discomfort seriously. Ask your veterinarian about recurring irritation or unusual anatomy. And treat formal veterinary screening—not internet percentages—as the tool for evaluating an individual dog.

Source

Lemle C, Koch C, Meyer-Lindenberg A. “Prevalences of Known and Presumed Inherited Eye Diseases in Pugs in Germany.” Veterinary Ophthalmology. First published July 29, 2026. https://onlinelibrary.wiley.com/doi/10.1111/vop.70235

This article is educational information and is not a substitute for veterinary diagnosis or treatment.