Health
A red eye, watering, brown gunk in the morning, one eye held shut. Conjunctivitis is the word that springs to mind; often it is something else, and eyes do not wait.
Caution. An eye held shut, a cloudy or bluish cornea, an enlarged hard eye with a wide pupil, unequal pupils, a dog walking into things, an injured eye or one out of its socket: see your own vet today. An eye out of its socket, right now.
Do not look for the answer in a Facebook group, on TikTok or on a forum. Look for someone trained for this: your dog's own veterinarian, the only person who can examine, investigate and treat them.
Use this page to know what to observe, what to note and what to ask at the appointment, not to treat at home. If you still have doubts after a consultation, ask another vet or a specialist (dermatologist, internist) for a second opinion, not a group. And if you do not have a regular vet yet, find one now, while your dog is healthy: how to choose a veterinary clinic.
This morning your dog is holding his left eye half shut. It is red and watering, and he keeps rubbing his face along the rug. Or your cocker wakes up every day with sticky brown gunk in the corners of his eyes; you wipe it away and by the next morning it is back. Or your old Labrador's eye has gone bluish and cloudy in the space of a few days. People type "conjunctivitis in dogs" into a search engine, and very often that is not what it is. It can be an ulcer on the cornea, high pressure inside the eye or a gland that has stopped making tears, and at first glance all three look like a red eye. Below is what you can check at home, why eyes are the one organ where the rule is "seen the same day", and what your own vet will do. What you will not find is which drops to use. With eyes, the wrong drops can cost a dog his sight within 24 hours.
The cornea is thin. An ulcer can go right through it in a day or two, and high pressure destroys the optic nerve within hours. Ring the same day if:
A red eye that waters clear tears and stays fully open, in a bright dog who is not in pain, can wait until tomorrow morning. A closed eye cannot.
Always compare with the other eye, in daylight, without forcing it open.
Which eye, and since when. One eye on its own points more often to something local: a scratch, a foreign body, an ulcer, pressure. Both eyes together point to irritation, allergy, poor tear production or an illness affecting the whole body.
How open it is. Fully, half, shut. Is he blinking more on that side? Avoiding light? A shut eye means pain, and eye pain means a vet today.
The discharge. Watery and clear comes from irritation, wind, allergy or a blocked tear duct. Thick, greyish-white, sticky, gathering in the corner and back again after you wipe it, means too few tears: dry eye. Yellow or green means infection, usually sitting on top of another problem. A little dry brown crust in the morning is normal in many breeds, especially when both eyes look the same.
Where the red is. Large, straight vessels across the white of the eye running towards the cornea point to something deep: pressure, or inflammation inside the eye. Red on the lids and on the pink lining inside them is on the surface, in the conjunctiva. Intense red everywhere with a hard eye means pressure.
The cornea. Shiny and clear is good. Cloudy, bluish, with a white dot or a dull patch: ulcer or inflammation. Vessels growing across the cornea like red threads mean the problem is old, weeks rather than days.
The pupils. Are they the same size? Shine your phone torch: do both close down, or only one? One big and one small is worth noting and mentioning on the phone.
The eyelids. Swollen, crusty. A pink lump in the inner corner, which is the gland of the third eyelid popping out ("cherry eye"). The lid edge rolled inwards with lashes on the eye, as in Shar Peis, Chow Chows and sometimes puppies. Or the lid sagging outwards like a pocket, in breeds with loose facial skin.
Sight. In a room he knows, silently drop a ball of cotton wool in front of him, half a metre away. A dog who can see follows it with his eyes. Repeat with each eye covered in turn by your palm, without touching it.
The lens. In old dogs the pupil takes on an even grey-blue sheen and the dog still sees well. That is normal ageing of the lens. Dense, chalky white in a dog who bumps into things is cataract. And a cataract that appears quickly in a dog who is drinking and weeing a lot is a reason to ask for a blood glucose test.
What happened beforehand. A walk through long grass or fields (a grass seed can lodge under the third eyelid), head out of the car window, wind, dust, a new dog or cat at home, yesterday's shampoo, dry air. Breed matters too. Cockers, Westies, bulldogs, pugs and Shih Tzus often get dry eye; cockers, Bassets and Huskies get glaucoma; breeds with prominent eyes scratch them easily.
| Problem | What you see | One eye or both | How soon |
|---|---|---|---|
| Irritation or allergic conjunctivitis | Red lids, watery discharge, itching, eye open | Usually both | Tomorrow, if it stays open and he is bright |
| Dry eye (too few tears) | Thick grey-yellow sticky discharge that keeps coming back; dull cornea | Usually both | This week; it is lifelong and treated for life |
| Corneal ulcer or scratch | Eye shut, watering, dull or bluish patch, pain | One | Today |
| Glaucoma (high pressure) | Intense red, hard enlarged eye, cloudy cornea, wide pupil, dog subdued | One, then the other is at risk | Today, within hours |
| Inflammation inside the eye (uveitis) | Small pupil, deep red, cloudy eye, avoids light | One or both | Today; often a sign of illness elsewhere |
| Foreign body (grass seed) | Sudden, one eye shut, watering, rubbing | One | Today |
| Cherry eye | Soft pink lump in the inner corner | One, often the other later | This week |
| Eyelid rolled inwards | Constant watering, eye half shut, lashes on the cornea | One or both | This week |
| Cataract | White, dense pupil; bumps into things | One or both | This week; today if he is drinking a lot |
| Ageing lens | Even grey-blue sheen, sees well | Both | At the next check-up |
Two pairs get mixed up all the time. Dry eye gets called "conjunctivitis that won't go away", and an ageing lens gets called a cataract. A one-minute tear test sorts out the first, an ophthalmoscope the second.
Wipe away the small, dry morning crust with cotton wool dampened in clean water, from the corner by the nose outwards, a fresh piece for each eye. Long hair in front of the eyes gets tied up or trimmed by someone with a steady hand. After a walk through long grass or fields, gently pull down the lower lids and look in both eyes. On windy, dusty days, check his eyes in the evening. And dogs with prominent eyes have no business playing rough with the cat.
Trailing dogs work with their noses down in grass, hedges and fields, so their eyes meet everything that grows there. That is why, for us, a look in the eyes after training is as routine as shaking out the harness. If you do not have a regular vet yet, our page on related services will help you choose a practice. Ask whether they do a tear test and the eye stain; any decent practice will.
What dog owners search for most often on the internet about this problem, with the short answer. The answers are a guide only: the decision belongs to your dog's own vet, after an examination.
Sometimes, when it is just irritation from wind or dust and the eye stays open: it settles in two or three days. But conjunctivitis that will not clear or keeps returning is almost always something else: dry eye, a rolled-in lid, allergy, a small ulcer. If it looks the same after two days, the discharge thickens or the eye starts to close, your vet should see it that day.
None without a vet check. Drops left over from an old problem, another dog or yourself can deepen an ulcer within a day. The same red eye needs different drops depending on the cause, and the cause shows up on the stain test and the tear test, a minute each. Until you get there, you can rinse with saline and stop him rubbing. That is all.
Ring today. A shut eye means pain, and the pain comes from an ulcer, a scratch, a grass seed under the lid or high pressure, where every hour counts. Until you get there, stop him rubbing (a cone or your hand), put nothing in the eye except saline if you suspect dust or a seed, and keep him out of bright light. On the phone, say how long it has been like this and whether he was hit.
Clear, watery tears from both eyes come from irritation: wind, dust, allergy, hair poking into the eye or a blocked tear duct (the brown staining under the eyes in small white breeds). Watering from one eye only, especially when it is half closed, means pain in that eye and needs seeing that day. The vet checks the lids, lashes, tear duct and cornea with stain.
Practically no. Infectious conjunctivitis is rare in dogs, and the germs involved are not the human ones. A red eye in a dog most often comes from irritation, too few tears or a problem with the eye itself, nothing catching. Wash your hands after cleaning his eyes as a matter of common sense, and do not use the same pad on both eyes or on several dogs.
The information on this page is educational and does not replace an examination. For full details and a diagnosis, consult your dog's own veterinarian.
They often come together: the same causes, plans that complement each other.
Claws on the belly at midnight, paws licked red, an ear infection every summer. Behind the word "allergy" sit at least three diseases, each with its own plan.
A goose-honk cough a week after kennels, a night-time cough in an old dog, bursts of sneezing after a field walk. Three sounds, three directions, one first step: film it.
Head shaking, scratching until he yelps, a yeasty smell. The ear is where it shows, the cause is usually elsewhere, and last time's drops will not find it.
He paces at night, stands with his nose in a corner, waits at the wrong side of the door, wees indoors. Some of it is age. Some of it can be treated.
We work with your dog's behaviour, not its health. For any sign described here, book an appointment with your own vet; the related services page explains how to choose a clinic.