When you talk about dental problems/watery eyes in senior rabbits, this is what it means:
Here is the link from Dana Kremple’s article: http://www.bio.miami.edu/hare/sneezing.html
Dental Disorders and Chronic Runny Eyes/Nose
Many people are surprised at how common dental problems are in rabbits, and even more puzzled to learn that such problems can cause symptoms such as runny eyes and nose. This is more often seen in older rabbits, as these have had time to develop molar spurs, or molar root problems that can cause inflammation or even develop into infections that spread to the sinuses.
In some older rabbits, gradual onset of metabolic bone disease results in loss of bone density (osteoporosis), especially in the already light bones of the skull. When this happens, the molar and/or incisor roots can very gradually be pushed into the thinning bone as the rabbit chews.
Because rabbit teeth grow continually, the visible portion of the teeth may appear entirely normal. It is only upon radiography that the root problem becomes visible as an intrusion of the tooth roots into the skull bones. This sometimes been called “root overgrowth,” though the term is a bit of a misnomer. The roots are not actually “growing” into the skull, but are being pushed there.
A rabbit’s molars are located almost directly under the eyes. Hence, molar root intrusion into the skull bones can cause occlusion (blockage) of the tear ducts, which run through the skull bones, close to the roof of the mouth, just above the tooth roots. A blocked tear duct will cause tearing and runny eyes, since the tears cannot flow through the ducts and into the back of the mouth, where the duct normally empties. A narrowed duct is more susceptible to becoming plugged with mucus or bacteria. If the duct is not completely occluded, it is often possible for your vet to flush the ducts and help restore normal flow. Whatever discharge comes out the nose from the flush can be A rabbit’s molars are located almost directly under the eye socket. When molar problems (spurs, root intrusion, abscess) develop, symptoms such as runny eyes can be a clue that something’s amiss. collected and sent to a lab for culture and sensitivity testing.
Severe molar root intrusion can also be the cause of retrobulbar abscesses (i.e., abscesses located behind the eye, inside the skull). In some cases, the root has been known to puncture through the bone of the eye socket and into the eyeball itself, causing an intraocular (i.e., inside the eyeball) infection. Such severe problems may require the expertise of a licenses veterinary ophthalmologist, and your own vet may be able to refer you to one in your area, if necessary.
Even incisor (front tooth) roots can be pushed backwards into the skull and occlude the tear ducts. Again, this is usually visible only with radiography. Although your vet may suggest that incisor or molar removal may solve the teary eye problem, there are no guarantees. If the chronic trauma to the area already has caused enough scarring in the bone, even tooth removal may not open a blocked duct. You and your vet should confer to decide whether complete tooth removal to attempt to restore tear duct function is worth the risk.