Tear stains on dogs are reddish-brown marks below the inner corner of the eye, and they are caused by porphyrins — iron-containing pigments released when the body recycles red blood cells — that are excreted in tears and dry onto the fur. The stain itself is a dye problem, not a disease. What matters clinically is why tears are sitting on the face instead of draining into the nose, and for most affected dogs that answer is anatomy rather than illness.
Short answer: Tear stains form when tears spill onto the fur (epiphora) instead of draining through the nasolacrimal duct. Porphyrin pigment in those tears oxidises and dyes light-coloured hair reddish-brown. Cleaning the face daily manages the appearance; only identifying and addressing the cause of the overflow changes the underlying problem — and in flat-faced or shallow-orbited breeds, that cause is often permanent conformation.
This article separates what is well established from what is widely repeated online without support. If you want the wider context on eyelids, discharge and routine ocular hygiene, our complete dog eye care guide covers the ground around this topic.
What exactly is a tear stain?
Two separate things are happening, and confusing them is the single biggest reason owners waste money.
Thing one: the tears are overflowing. Tears are produced continuously, spread across the eye by blinking, and drained through two small openings (the lacrimal puncta) at the inner corner of the lids into the nasolacrimal duct, which empties into the nose. The Merck Veterinary Manual describes this drainage pathway and the disorders that interrupt it, including dacryocystitis (inflammation of the tear sac) and imperforate lacrimal puncta, where the duct openings are absent from birth. When drainage fails or is simply outpaced, tears run down the face. That overflow is called epiphora.
Thing two: the fur is being dyed. Porphyrins are pigmented, iron-containing compounds excreted in tears, saliva and other secretions. Once tears dry on hair, the porphyrin remains and darkens with exposure to air and light. This is why the stain persists on hair that is already stained even after the tearing stops — the pigment is bound to the hair shaft, not sitting on the skin.
Fixing thing two without addressing thing one gives you a clean face for about a day.
Why does my dog have tear stains?
Because tears are landing on hair. The reasons they land there fall into a few clear groups, and a veterinary exam is aimed at telling them apart.
| Likely cause | What it typically looks like | What a vet typically checks |
|---|---|---|
| Conformation (shallow orbit, prominent globe, large eyelid opening) | Both eyes, chronic, present since puppyhood, dog is comfortable and not squinting | Eyelid anatomy and lid-to-globe fit; whether the lower punctum is positioned to collect tears at all |
| Medial entropion / hair on the caruncle | Both eyes, chronic, sometimes mild redness at the inner corner; common in flat-faced and toy breeds | Lid margin rolling inward at the inner corner; whether hair is wicking tears onto the face |
| Blocked or absent nasolacrimal puncta / duct | Often one eye, wet face on that side only, no other signs of pain | Fluorescein applied to the eye to see if dye appears at the nostril; duct flushing under sedation if it does not |
| Dacryocystitis (infected tear sac) | Persistent watery-to-mucky discharge, conjunctivitis that keeps coming back despite treatment | Pressure over the tear sac, duct flushing, sometimes contrast imaging for chronic obstruction |
| Distichiasis / ectopic cilia (misplaced lashes) | Squinting, blinking, tearing that appears suddenly in a young dog | Lid margins under magnification; corneal staining for ulceration |
| Ocular surface irritation (allergy, dust, conjunctivitis, corneal ulcer) | Sudden onset, redness, pawing, discharge that changes colour or thickness | Schirmer tear test, fluorescein stain, full ocular exam |
| Secondary skin infection in the wet fold | Damp, sticky, sometimes odorous fur; skin under the stain is pink or inflamed | Skin cytology from the fold to look for yeast or bacteria |
Brachycephalic breeds sit at the intersection of several of these. A 2023 review in Veterinary Ophthalmology describes brachycephalic ocular syndrome as a cluster of conformation-driven ocular surface problems — shallow orbits, an oversized eyelid opening, medial entropion and nasal folds — and its authors describe the prevalence as concerningly high and frame it as a welfare question (Sebbag and Sanchez, 2023). In a separate case series of 93 brachycephalic dogs presented for ophthalmic examination, Costa and colleagues reported corneal ulcers in 44%, corneal pigmentation in 36% and entropion in 22% of that referral population (Costa, Steinmetz and Delgado, Irish Veterinary Journal, 2021). Those figures describe dogs seen in that study, not the risk facing any individual dog.
Light-coated dogs are not more likely to have epiphora; they are simply the ones on whom the pigment shows. A Maltese with the same tear volume as a black Labrador will look dramatically worse.
Is the discharge normal, or is something wrong?
A small amount of crust at the inner corner in the morning is ordinary. Clear, watery overflow that is chronic, symmetrical and painless is usually anatomical. What is not ordinary is discharge that changes character — thicker, yellow, green, or increasing — or discharge on one side only in a dog that previously had none. We break down the normal-versus-concerning distinction in more depth in our guide to dog eye discharge and eye boogers.
Can the stained fur itself become a problem?
Yes, and this is the part most articles skip. Fur that stays damp against skin creates the conditions for intertrigo — skin fold dermatitis — where Malassezia yeast and bacteria overgrow. As reported by O’Neill and colleagues in a UK primary-care study of 905,553 dogs, the one-year period prevalence of skin fold dermatitis was 0.37% overall, 1.02% in brachycephalic breeds versus 0.26% in mesocephalic breeds, and 6.05% in English Bulldogs (Scientific Reports, 2022).
If the stained area smells, feels greasy, or the skin beneath is pink and sore, the issue has moved past cosmetics and needs a veterinary look.
What at-home approaches actually have evidence behind them?
Here is an honest audit. “Evidence strength” refers to published veterinary or scientific evidence for reducing tear staining specifically — not to how popular the approach is.
| Approach | How it is meant to work | Evidence strength | Honest notes |
|---|---|---|---|
| Daily wiping of the wet fur with a soft, damp pad or dog-specific eye wipe | Removes tears before porphyrin oxidises and keeps the fold dry | Moderate (mechanistically sound, low risk, universally recommended by clinicians) | Does not remove pigment already bound to the hair. Consistency beats intensity. |
| Keeping the hair around the inner corner trimmed short | Stops hair wicking tears onto the face and reduces the damp surface | Moderate | Best done by a groomer or vet; never use scissors pointing toward the eye. |
| Veterinary treatment of an identified cause (duct flush, entropion or lash correction, treating conjunctivitis) | Reduces tear overflow at source | Strong, where a specific cause is found | Only helps if there is a correctable cause; conformation often is not fully correctable. |
| Growing out or clipping away stained hair | Physically removes dyed hair shafts | Strong for appearance | The only reliable way to remove existing stain. Requires patience. |
| Switching to filtered, bottled or distilled drinking water | Assumed mineral or iron content contributes to staining | Limited to anecdotal | No controlled canine study supports this. Harmless, but not a fix. |
| Changing food or protein source | Assumed dietary iron or ingredient sensitivity drives porphyrin output | Limited | Plausible in dogs with a genuine dermatological allergy; unproven as a general remedy. |
| Dietary botanical supplements | Proposed effects on iron and porphyrin metabolism | Limited — one small trial | See below. |
| Tylosin-containing “tear stain removers” | Antibiotic suppression of bacteria on the face | Not appropriate — regulatory action taken | See below. |
| Hydrogen peroxide, makeup remover, or human whitening products on the face | — | Not recommended | Risk of chemical injury to the ocular surface. Avoid entirely. |
If you are comparing commercial options, our roundup of tear stain removers for dogs explains what the ingredient lists actually do, and our review of dog eye wipes covers the daily-cleaning end of the shelf.
The tylosin question
Many older “tear stain” powders contained tylosin tartrate, an antibiotic. In August 2014 the FDA issued warning letters to three Florida-based companies over unapproved tear stain products, including the Angels’ Eyes, Angels’ Glow and Pets’ Spark lines, as reported by AVMA’s JAVMA News. Tylosin is not approved for any use in dogs or cats, and the agency’s objection was that the companies claimed their products kill bacteria, eliminate infections or treat the conditions causing the stains — claims that make a product a drug. Feeding a low-dose antibiotic indefinitely for a cosmetic reason is also poor antimicrobial stewardship. Brands here have changed formulations since, so the only reliable check is the ingredient panel in front of you: if an antibiotic is named, put it back.
The supplement question
One 2026 study in Animals by Wang and colleagues fed 40 Poodle and Bichon dogs diets supplemented with Chrysanthemum morifolium, Cassia semen or Poria cocos at the inclusion rate used in that study (0.5% of the diet) and reported lower tear staining scores and shorter stain length versus control, alongside changes in serum iron, ferritin and porphyrin-related markers. That is genuinely interesting, and it is also one small, single-population trial in two breeds — not grounds for expecting a supplement to resolve staining in your dog. Research suggests a mechanism worth investigating; evidence remains limited.
When to call your vet
Book an appointment rather than reaching for a wipe if you see any of the following:
- Squinting or holding the eye partly closed — a pain signal, not a cosmetic one
- Redness of the white of the eye or the inner lid
- Pawing or rubbing the face on furniture or carpet
- Sudden onset of tearing in a dog that did not previously tear
- Discharge changing colour or consistency — clear to yellow, green, or thick and mucky
- One eye only, especially if it appeared abruptly
- Cloudiness of the cornea, a visible blue or white haze, or a change in eye size
- Skin under the stain that is inflamed, sore or odorous
Any of the first six can indicate a corneal ulcer, foreign body, blocked duct or infection. Our overview of the signs of a dog eye infection explains how these present and why same-week attention matters.
How long until you see a difference? A realistic timeline
| Timeframe | What is realistic |
|---|---|
| Days 1–7 | The face stays cleaner and drier with twice-daily wiping. Existing stain is unchanged. |
| Weeks 2–4 | Any damp-fold irritation should be settling if hygiene is consistent. Newly grown hair at the base emerges unstained if tearing has been reduced. |
| Weeks 4–12 | Visible fading as stained hair is trimmed away or grows out. Rate depends entirely on facial coat growth and grooming frequency. |
| Beyond 3 months | If staining is unchanged despite consistent care, the overflow has not been addressed. This is the point to pursue a veterinary work-up rather than a new product. |
Dogs whose epiphora stems from conformation will keep producing new stain indefinitely. For them, the goal is maintenance rather than resolution.
Common mistakes owners make
- Treating the stain and ignoring the tearing. Bleaching the fur while the eye still overflows is a permanent treadmill.
- Getting product into the eye. Anything marketed for fur belongs on fur. Nothing goes on the ocular surface unless a veterinarian prescribes it.
- Assuming one wet eye is the same as two. Unilateral tearing points toward an obstruction, foreign body or ulcer far more often than bilateral tearing does.
- Skipping cytology on an angry-looking fold. Yeast and bacterial overgrowth need targeted treatment, not more wiping.
- Wiping hard. The skin at the inner canthus is thin and close to the cornea. Blot and dab; do not scrub.
- Buying an antibiotic-containing powder. Read the ingredient panel rather than the marketing copy.
- Expecting a diet change to work in a week. If a dietary trigger exists at all, an elimination trial is a multi-week protocol run with veterinary guidance.
Frequently asked questions
Are tear stains on dogs painful?
The stain itself is not. The tearing behind it may be, especially where misplaced eyelashes, entropion or a corneal ulcer are involved. Squinting, redness or pawing indicates discomfort and warrants a veterinary exam.
Can tear stains on dogs go away permanently?
Porphyrin pigment already bound to the hair shaft does not wash out; that hair has to grow out or be trimmed away. Whether new staining stops forming depends on whether the cause of the overflow can be corrected. For conformation-driven epiphora, ongoing management rather than cure is the realistic goal.
Does distilled or bottled water stop tear stains in dogs?
No controlled study in dogs supports this. It is a low-risk thing to try, but the evidence remains limited and it should not replace a veterinary assessment of persistent tearing.
Why does my white dog have tear stains but my black dog does not?
Both dogs may have similar tear overflow. The reddish-brown porphyrin pigment in tears is simply visible against light-coloured hair and effectively invisible against dark hair.
Is it safe to use human eye makeup remover or hydrogen peroxide on dog tear stains?
No. These products carry a real risk of chemical injury to the eye and surrounding skin, and neither is formulated for use near the canine ocular surface.
Which dog breeds get tear stains most often?
Light-coated toy breeds such as the Maltese, Bichon Frise, Poodle and Shih Tzu show tear staining most visibly. Brachycephalic breeds are anatomically predisposed to the ocular surface problems that drive tear overflow.
References
- Gelatt KN. Disorders of the Nasal Cavity and Tear Ducts in Dogs. Merck Veterinary Manual (Pet Owner Version). Full review Jun 2018, last updated Sept 2024. https://www.merckvetmanual.com/dog-owners/eye-disorders-of-dogs/disorders-of-the-nasal-cavity-and-tear-ducts-in-dogs
- Sebbag L, Sanchez RF. The pandemic of ocular surface disease in brachycephalic dogs: The brachycephalic ocular syndrome. Veterinary Ophthalmology. 2023;26(Suppl 1):31-46. DOI: 10.1111/vop.13054. PMID: 36585820. https://onlinelibrary.wiley.com/doi/10.1111/vop.13054
- Costa J, Steinmetz A, Delgado E. Clinical signs of brachycephalic ocular syndrome in 93 dogs. Irish Veterinary Journal. 2021;74:3. DOI: 10.1186/s13620-021-00183-5. PMID: 33494828. https://pmc.ncbi.nlm.nih.gov/articles/PMC7836154/
- O’Neill DG, Rowe D, Brodbelt DC, Pegram C, Hendricks A. Ironing out the wrinkles and folds in the epidemiology of skin fold dermatitis in dog breeds in the UK. Scientific Reports. 2022;12:10553. DOI: 10.1038/s41598-022-14483-5. PMID: 35794173. https://www.nature.com/articles/s41598-022-14483-5
- American Veterinary Medical Association (JAVMA News). FDA warns makers of unapproved ‘tear stain’ products. Published October 2014. https://www.avma.org/javma-news/2014-10-15/fda-warns-makers-unapproved-tear-stain-products
- Wang E, Wu P, Xu J, Hong X, Zhao N, Sun T, Zhang T, Xu Z, Yang C. Effects of Traditional Chinese Herbal Extracts on Tear Staining, Iron Status, Immune Function, and Antioxidant Capacity in Dogs. Animals (Basel). 2026;16(11):1596. DOI: 10.3390/ani16111596. PMID: 42278031. https://pmc.ncbi.nlm.nih.gov/articles/PMC13255681/
Veterinary disclaimer: This article is for general educational purposes and does not replace veterinary examination, diagnosis or treatment. Dog Health Insider is an independent publication. Any dose or inclusion rate mentioned here is reported as it appeared in the cited study and is not a recommendation. If your dog is squinting, has red eyes, sudden or one-sided tearing, or discharge that is changing, contact your veterinarian promptly.