There are many causes of runny, watery eyes in rabbits. Runny eyes are not life threatening per se, but they may be symptoms of a more serious underlying condition. The continually wet fur and skin is also an ideal environment for the growth of bacteria and fungi, resulting in inflammation, fur loss and discomfort. The medical term for an abnormal overflow of tears is 'epiphora', which sounds like it ought to be something pleasant (‘I was simply epiphoric at the news!’) but in actuality it isn't pleasant at all.
A previous article discussed the functioning of the normal rabbit tear duct (the tube that drains the excess tears from the eye) as well as conditions which contributed to the narrowing and/or obstruction of the duct. Rabbits with runny eyes may appear to have been crying; the fur just under the eyes may be wet, or the fur of the cheeks may be damp or wet. A white, stringy discharge from the eyes may be present – these are all signs that your rabbit needs to be evaluated by a rabbit-savvy veterinarian. The causes of watery eyes in rabbits are myriad and a correct diagnosis is required to effectively treat this condition.
In addition to conditions which cause the tear duct (the ‘drain’ for the tears) to become obstructed (the drain ‘backs up’), other conditions cause so many tears to be produced that even an unobstructed ‘drain’ cannot keep up. Watery eyes can be an allergic reaction to dust from hay, pelleted food, or from volatile odors (avoid the pine litter) or fumes from a poorly ventilated/poorly cleaned litter pan.
Infections – including upper respiratory infections - can cause the eyes to produce more/thicker/stickier tears in attempts to soothe/protect themselves. Conjunctivitis and infections of the tear duct itself can result in watery eyes. Conjunctivitis is an inflammation of the mucous membranes covering the eye (including the nictitating membrane - aka the ‘third eyelid’) as well as the inside of the eyelids, and often results in a thick, sticky eye discharge. Causes of conjunctivitis may be viral, bacterial, a result of trauma, or a reaction to allergens or the afore-mentioned volatile odors. Rabbits with runny eyes need to be promptly evaluated by a rabbit-savvy veterinarian because bacterial infections can quickly spread to the jaw (forming an abscess) or to the respiratory tract. Antibiotics will need to be prescribed and begun immediately.
An injury to the cornea is painful, and can develop into a corneal ulcer. The cornea is the transparent ‘covering’ over the pupil (black part) and iris (colored part) of the eye (it’s like the eye’s ‘screen protector’). The cornea is easily injured, and given the fact that rabbits only blink a couple of times a minute, that cornea is exposed to the environment almost all of the time. Even a corneal injury invisible to the naked eye can cause copious tears or other eye discharge, redness, sensitivity to light, squinting and/or holding the eye shut. Immediate veterinary attention is required.
External trauma may damage to the cornea, and any condition which decreases the amount of tears to the eye will make the cornea more susceptible to becoming damaged. A ‘dry eye’ is more prone to scratches from hay or bunny's overly zealous face-washing. A corneal injury may degenerate into a corneal ulcer which may appear as a cloudy white spot on the eye – in addition to the pain it causes, it threatens the vision of the eye as well.
Your rabbit-savvy veterinarian will prescribe medications and eye drops and/or ointments to help the eye heal. Medications may include a combination of antibiotics, anti-fungal medications and eye drops to ease the pain. Once the cornea has healed, the excess tears will stop.
A misshapen eyelid can also have an effect: a congenital condition known as entropion (eyelids are rolled inward) results in the eyelid and eyelashes rubbing against the cornea. Entropion can not only cause watery eyes, but painful ulcerations on the cornea as well. If the eyelids roll outward (this condition is ectropion), the eyes will become irritated and the tears will flow over the droopy lower eyelids and onto the cheek instead of into the tear ducts. Even eyelashes growing at the odd angle can irritate and scratch the eye.
Rabbits also have meibomian glands (as we do) which are located inside the rim of the upper and lower eyelid. These glands normally produce a lubricant to slightly thicken normal tears. Inflammation or other impairment of these glands can result in epiphora.
The correct diagnosis and treatment for any of these conditions must be made by your exotics veterinarian.
Next: still more causes of watery eyes in rabbits, plus diagnostic and treatment options
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