Rabbit runny eye and tear staining: why it is usually a tooth problem

Quick answer

This is the baseline: both eyes clear, the fur below them dry, and no clumping at the inner corner. Compare left with right every time you groom.

A rabbit with a permanently wet eye and stained fur below it almost never has a grooming problem. It usually has a dental problem.

The tear duct that drains a rabbit's eye passes directly alongside the root of the upper incisor on its way to the nose. Rabbit teeth grow continuously, and when the crowns do not wear down properly the roots elongate into the bone and squeeze that duct shut. The tears then have nowhere to go except down the face.

• Treat a wet eye as a reason to have the teeth and skull examined, not as a cleaning task.
• Clean the fur to prevent skin scalding, but understand that cleaning treats the consequence, not the cause.
• A squinting, painful eye is a different and more urgent problem than a wet but comfortable one.
• In an unvaccinated rabbit, swollen sticky eyelids can be the first sign of myxomatosis.
• A permanently wet face in warm weather is a flystrike site. Check it twice a day in summer.

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An unvaccinated rabbit with swollen, crusted or sticky eyelids may have myxomatosis, which is usually fatal.

Myxomatosis typically begins around the eyes and the face, with swelling of the eyelids, thick discharge, and later swelling of the nose, ears and genitals. It spreads by biting insects and by direct contact, and indoor-only rabbits are not safe from it. If your rabbit is not vaccinated and its eyes have become swollen and sticky, contact a vet the same day and say that it is unvaccinated. Vaccination against myxomatosis and rabbit haemorrhagic disease is the single most important preventive step in this whole article.
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Decide in 60 seconds

Why the tooth and the eye are the same problem

Tears are produced continuously, wash across the eye, and drain into two tiny openings at the inner corner. From there they pass into the nasolacrimal duct, which carries them down through the skull and out into the nose. That is why a person's nose runs when they cry, and why a rabbit's should too.

In a rabbit, that duct takes an awkward route. It runs forward through the maxilla and passes right beside the root of the upper incisor before making a sharp bend and continuing to the nasal opening.

Rabbit teeth are open-rooted and grow continuously, for life. They are meant to be worn down at the same rate by hours of sideways grinding on long-fibre forage. Hay and grass do that. Pellets and mixed muesli do not, because they are crushed in a few vertical movements and swallowed.

When the crown does not wear away, the tooth still grows. The growth has to go somewhere, so the root elongates in the opposite direction, into the bone. That is called apical elongation, and it is the root cause of most rabbit dental disease.

An elongated upper incisor root sits exactly where the tear duct runs. It narrows or occludes the duct. Tears stop draining, spill over the lower lid, and run down the face.

The same process produces the other classic rabbit dental problems: spurs on the cheek teeth that lacerate the tongue and cheek, tooth root abscesses that appear as hard swellings on the jaw, and facial pain that stops a rabbit eating hay, which makes the whole thing worse.

The sharp bend in the duct matters too. It makes the duct easy to block and difficult to flush, and it is why flushing sometimes has to be repeated and why it fails altogether when a tooth root is the obstruction.

The differentials, and the feature that separates each

Simple blocked duct from tooth root elongation.

Clear watery overflow, comfortable eye, no redness, often one side worse than the other. The rabbit is not squinting. This is the commonest picture and it is a dental case.

Dacryocystitis, an infected tear sac.

Thick white or creamy discharge, often able to be expressed at the inner corner, sometimes with reddening of the surrounding skin. Frequently follows or accompanies dental disease, and the bacteria involved often include Pasteurella. Needs flushing and treatment, and will recur if the tooth is not dealt with.

Conjunctivitis.

Reddened conjunctiva, discharge, both eyes commonly involved. Look hard for a cause in the environment: ammonia rising from a litter tray that is not cleaned often enough is a potent irritant to mucous membranes, and so is dusty hay or dusty litter.

Corneal ulcer.

The painful one. The rabbit holds the eye shut or blinks hard, rubs at it with a forepaw, and the surface may look dull or have a visible defect. Needs fluorescein stain to confirm, and needs seeing quickly, because an ulcer that deepens can perforate.

Foreign body.

Classically a hay seed or fragment lodged under the third eyelid. Sudden onset, one eye, painful, and often obvious once the eye is examined properly.

Entropion.

The eyelid rolls inward so the lashes and fur rub the cornea. Persistent tearing plus discomfort, and it needs surgery rather than management.

Encephalitozoon cuniculi.

This parasite can cause a specific rabbit eye problem in which the lens is damaged and a white mass appears inside the eye, along with inflammation. It is the same organism behind the classic head tilt, and the two can appear in the same rabbit.

Retrobulbar disease or thymoma.

A bulging eye. A retrobulbar abscess usually affects one eye and is often dental in origin. A thymoma classically causes both eyes to bulge, sometimes intermittently, being most obvious when the rabbit is stressed or restrained.

Glaucoma.

An enlarged, hard, often cloudy eye. Inherited glaucoma is recognised in New Zealand White rabbits.

Myxomatosis.

See the danger box. Swollen sticky eyelids in an unvaccinated rabbit, progressing to facial and genital swelling.

Staging: what early, established and late look like

Early. Intermittent dampness at the inner corner, noticeable after the rabbit has been eating or grooming. A faint discolouration of the fur below the eye that you might put down to dirt. The rabbit is entirely well and eating normally.

This is the stage at which the underlying dental problem is most treatable, and it is almost always missed because nothing looks wrong.

Established. The fur below the eye is permanently damp and stained, and clumps into a tract. The skin underneath is pink and beginning to thin. Discharge may have thickened. The rabbit may be selecting soft food and leaving hay, which is the dental sign owners most often miss because the bowl still empties.

Late. Hair loss below the eye, sore inflamed skin, thick discharge, matting, sometimes a visible facial swelling from an abscessed tooth root. Weight loss. In summer, this is a flystrike site.

The progression is slow, measured in months, which is exactly why it is worth acting on the early stage.

The home routine that catches it

Check the head as one unit. Ears, eyes, nose and jaw line share a skull, and in lop breeds problems in one often accompany problems in another.

Cleaning the face without making it worse

Warm water, plain cotton wool, and something to dry with. Nothing on this tray goes into the eye.

The point of cleaning is to stop the skin scalding, not to treat the eye.

Use warm water on plain cotton wool or a soft cloth. Soften crusts by holding the damp cotton wool against them rather than rubbing. Wipe outwards, away from the eye, using a fresh piece for each eye so you do not carry infection across.

Dry the area properly afterwards. Leaving it damp is the whole problem, and a rabbit whose face is wiped and then left wet is worse off than one that was not wiped at all.

Use plain water unless your vet has given you something specific. Do not use human eye drops, contact lens solution, baby shampoo, antiseptics, salt water, tea, or any tear-stain product marketed for dogs. Several of the latter contain antibiotics, some human drops contain steroids that make a corneal ulcer dramatically worse, and none of them address a compressed tear duct.

Do not trim the fur below the eye with scissors. Rabbit skin is exceptionally thin, tents easily and is cut without the person noticing. If matting needs removing, it is a job for clippers in experienced hands.

Fixing the cause: hay is the treatment

If tooth root elongation is behind the wet eye, then the long-term answer is the diet that keeps the crowns wearing.

That means unlimited good grass hay available at all times, treated as the bulk of the diet rather than as bedding. A rabbit should be eating roughly its own body size in hay each day.

Pellets are a supplement, given in a measured small amount. Muesli mixes should be replaced entirely, because selective feeding of the sweet components leaves the fibrous ones uneaten and is directly linked to dental and gut disease.

Fresh leafy greens add variety and chewing. Sugary treats, bread, cereal and yoghurt drops do not.

This will not reverse roots that have already elongated. It stops the process getting worse, which in a young rabbit changes the whole trajectory, and in an older one reduces how often intervention is needed.

What the vet will do, and what to bring

Expect a full head examination, which in a rabbit means more than looking in the front of the mouth. The incisors are visible, but the cheek teeth are not, and a proper assessment usually needs sedation or anaesthesia and imaging.

Expect fluorescein stain if there is any suggestion of pain, to look for a corneal ulcer.

Expect the tear duct to be flushed, using a fine cannula through the opening at the inner corner. This is often done under sedation, and material flushed out may be sent for culture. Flushing may need repeating, and it will not hold if a tooth root is the obstruction.

Expect a discussion about skull radiographs or a CT scan, which is what actually shows the tooth roots and their relationship to the duct.

What changes by breed, age and season

Lop breeds. Altered skull shape, a higher rate of dental disease, narrowed ear canals, and disproportionate numbers of duct problems. Lops need their head checked more often, not less.

Dwarf breeds, including Netherland Dwarf and Lionhead. A shortened upper jaw crowds the teeth, so both malocclusion and duct compression are commoner. Congenital incisor malocclusion often shows in the first few months.

New Zealand Whites. Inherited glaucoma is recognised in this breed, so an enlarging or cloudy eye deserves specific attention.

Young rabbits. A wet eye in a young rabbit is more likely congenital malocclusion or a foreign body than acquired root elongation.

Older rabbits. Years of a low-hay diet catch up. Acquired dental disease is the usual explanation, often with abscesses.

Summer. The season changes the urgency. A permanently damp, matted patch of fur on a rabbit's face is an invitation to flies, and flystrike can go from eggs to burrowing maggots very quickly in warm weather. Twice-daily checks of both the face and the back end are not optional in summer.

Winter. Dry heated air, dusty hay stored indoors, and less frequent litter changes because of the cold all irritate eyes.

What never to do

Never put human eye drops in a rabbit's eye. Steroid-containing drops make corneal ulcers worse, and some preparations are directly harmful.

Never use tear-stain removers sold for dogs. Several contain antibiotics, which should not be given without a diagnosis, and none of them will move a tooth root.

Never trim fur near the eye with scissors.

Never pick crusts off. Soften them and wipe them away.

Never wipe and leave the area wet. Drying is the part that protects the skin.

Never treat this as cosmetic. A wet eye in a rabbit is a symptom of a disease process in the skull, and it will progress.

Never skip vaccination. The most dangerous cause on this page is also the one that is entirely preventable.

When to get help

The aim is a dry face and a rabbit still eating hay, with the dental cause found while it was still just a damp inner corner.

Contact a rabbit-experienced vet the same day for a squinting or painful eye, a cloudy or bulging eye, a white mass inside the eye, swollen sticky eyelids in an unvaccinated rabbit, or a rabbit that has a wet eye and has also stopped eating.

Treat it as an emergency if you find maggots or fly eggs anywhere on the rabbit, or if the rabbit has stopped eating and passing droppings, because gut stasis moves faster than any eye problem.

Book within the week for a persistently damp eye, brown-stained fur, thick discharge, or a rabbit that has quietly stopped eating hay while still finishing its pellets.

The appointment worth asking for is a dental and skull assessment, not an eye appointment. In this species those are usually the same consultation, and the eye is the part you can see.