Epiphora is the term used to describe the overflow of tears on to the skin of the lower eyelid. This condition occurs if there is an overproduction of tear fluid, an inadequate drainage of tear fluid or a combination of both. If the epiphora is severe, the skin below the eyelid becomes secondarily infected due to the favorable (wet) environment that is established. If the color of the fur is light then the enzyme that is contained in the tear fluid will stain the fur an unsightly dark brown color.
An irritant such as misplaced hairs on the lower eyelid margin, or a rolling inward of the eyelid margin (entropion), or a foreign body such as plant material, or an ulcer on the cornea of the eye are all examples of what can cause the overproduction of tears. Tumors of the eyelid usually are not considered irritants but rather affect the drainage system capabilities. Any plugging, scaring or kinking of the nasolacrimal duct will decrease the drainage capacity and result in a backup and overflow similar to a plugged toilet in your house.
Close examination of the eye with an ophthalmascope is needed to diagnose misplaced hair(s) along the eyelid or a foreign body in the conjunctiva or on the cornea. A fluorescein dye is needed to diagnose an ulcer to the cornea or inadequate drainage through the nasolacrimal duct due to a blockage. The dye will highlight an ulcer if one is present and will not be seen coming out the nose if there is a blockage. Entropion can be assessed by applying gentle pressure to the eyelid and observing that there is an outward rolling of the hairs along the margin before you get to the conjunctiva.
Treatment is directed toward the underlying cause. In the case of misplaced hair(s), removal or epilation is necessary to solve the epiphora. Any foreign must also be removed before the epiphora will stop. If an ulcer is present then frequent applications of medication and follow up assessments are needed. In most cases tumors of the eyelid can be removes surgically without too much disfigurement. Introducing a catheter into the nasolacrimal duct and flushing out any debris is often successful in unplugging the drainage system if it is not scared closed. In all cases, once the proper treatment has begun a marked improvement should be seen in a short time. As the epiphora disappears any secondary infection of the skin below the eye should also clear up.
In stubborn cases treatment may not be totally successful or the underlying cause may return. In most cases your veterinarian will be able to significantly improve this condition or he/she may decide to refer you to a specialist.