Previous articles have discussed obstructed tear ducts and several other causes for runny, watery eyes in the house rabbit. Another cause for runny eyes may be glaucoma. Glaucoma in rabbits is uncommon but it does occur, resulting in increased pressure in the eye. Watery eyes may be a symptom, but by the time you see symptoms, the glaucoma is usually advanced and immediate treatment is needed in order to save the rabbit’s vision.
In the normal eye, a thick fluid fills the “eyeball” (the space between the cornea and the lens of the eye) and gives the eye it’s round(ish) shape (among other functions). This fluid (known as the aqueous humor for those of you trying out for Jeopardy) is constantly being produced and the excess is drained off via channels at the base of the cornea. With glaucoma, more fluid comes into the eye than is drained off. The pressure inside the eye increases and this pressure can damage the retina and the optic nerve, causing blindness.
There are usually no observable symptoms early on. Advanced glaucoma can cause the eyeball to enlarge and cause inflammation of the surrounding tissues. Sometimes the eye may become watery because of the inflammation. If your rabbit’s eye EVER appears larger than normal, immediate veterinary attention is required.
Neurological disorders can certainly be the cause of watery eyes. Facial nerve paralysis resulting from surgery, trauma, or a disorder of the central nervous system (stroke, Bell’s palsy, head tilt) can lead to watery eyes. Sometimes the eyelids droop and allow tears to overflow, and sometimes damaged nerves can no longer stimulate the lacrimal pump which sends tears through the tear ducts. Head tilt can sometimes leave one eye unable to ‘blink’ and the permanently open state of that eye leads to dry eye and increased chance of abrasions and injury.
Some of these conditions can be treated with appropriate medications, but congenital or unresponsive problems may need surgical repair.
Your bunny-savvy veterinarian will have diagnostic tools to help determine the cause of the watery eyes in your rabbit. Simple tests such as testing for light sensitivity offer clues, as will staining the eye with a temporary dye and viewing with ultraviolet light to reveal corneal ulcers or fungal infection. Culture and sensitivity testing might be necessary if bacterial infection is suspected. Various types of imaging (radiography, ultrasound, and endoscopy) can be used to determine if abnormal masses are present. Owing to the seemingly endless causes of epiphora, more than one diagnostic technique may be necessary to determine the cause of your bunny’s ailment.
Treatment depends upon the cause of the epiphora, of course. Treatment for a simple case of irritation caused by allergens may be as simple as some ophthalmic lubricating ointment such as PuraLube, SteriLube, Celluvisc, Lacrilube or other over-the-counter nighttime ointment.
A diagnosis of cellular debris blockage may require only ophthalmic antibiotics drops and some corticosteroids to reduce inflammation. If this does not resolve the problem, a tear duct flush (or a series of flushes) may be recommended; dental or sinus infections may require other systemic medications.
Anti-inflammatory medications, antibiotics, and/or antifungal medications are all in your veterinary’s arsenal depending on the pathogen(s) and/or processes involved.
It is not uncommon for epiphora to recur, and often long-term attention to the area may be necessary. A moist, warm cloth can be used to wipe tears, and a warm wet compress will soften and loosen debris from the fur. Removing this debris prevents further matting of the fur and prevents a bacteria-friendly environment; the warm compress can also help with any swelling in the area. An attentive bonded bunny companion might groom the area for you and keep the bunny more comfortable.
In some cases the fur under the cheek may peel off due to irritation from constant tearing. Your veterinarian can prescribe a soothing topical ointment or prescription topical anesthetic power to be applied to absorb moisture (keeping the powder away from the eye of course).
Remember: any changes in your rabbit’s vision and/or the appearance of the eye itself or the surrounding area should be promptly evaluated by your rabbit-savvy veterinarian.
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