Epiphora is a disease of the lacrimal apparatus marked by an abnormal overflow of tears down the cheek or face. Tears are formed by lacrimal (tear) glands and their function is to lubricate the cornea, supply nutrients, and carry away wastes. The tears drain out through a tear duct from the eye to the nose. Epiphora is caused by an overproduction or an inadequate removal of tears caused by blockage of the tear ducts, although often the cause is unknown. Epiphora often occurs as a result of conjunctivitis and keratitis and in these cases it is due to overproduction of tears from the eye irritation, although sometimes there is blockage of the ducts as well. The overflow of tears down the face or cheek is readily visible in epiphora, especially in dogs with light-colored or white hair.
To determine if the tear ducts are blocked, a special test using a staining solution is performed. Unfortunately, in poodles the cause of epiphora is not always readily determined. Sometimes, a low-grade infection of the nose and throat causes partial or complete blockage of tear ducts. If the epiphora recurs when the antibiotics are stopped, the tonsils will need to be checked since they may be the source of the infection. Cases caused by blockage of the tear ducts often respond to medical treatments with antibiotic eye ointment and sometimes oral antibiotics, but many require flushing the ducts under anesthesia or surgical opening of the ducts. If the epiphora is due to an eye diseases, such as conjunctivitis and keratitis, then treatment of these diseases will usually clear up the problem. In some chronic cases that do not respond to therapy, surgical removal of the third eyelid helps reduce tear production. The disadvantage of this procedure is that the tear production may then be inadequate, and this can lead to other eye problems. If the cause of epiphora cannot be determined, or if it becomes chronic despite treatments, the dog owner must learn to live with the problem. Although the cosmetic effect of epiphora is unattractive, the dog's eyes and health are usually not affected in such cases. Daily washing and frequent clipping of the hair in the affected area will keep the staining to a minimum.
Other disease of lacrimal apparatus include:
- Lacrimal Duct Obstruction - Interference with the secretion of tears by the lacrimal glands. Obstruction of the lacrimal sac or nasolacrimal duct causing acute or chronic inflammation of the lacrimal sac (dacryocystitis); the occlusion may occur spontaneously or after injury or nasal disease.
- Dacryocystitis - Inflammation of the lacrimal sac
- Dry Eye Syndrome
- Keratoconjunctivitis Sicca - Drying and inflammation of the conjunctiva as a result of insufficient lacrimal secretion.
- Xerophthalmia - Dryness of the eye surfaces caused by deficiency of tears or conjunctival secretions. It may be associated with vitamin A deficiency, trauma, or any condition in which the eyelids do not close completely.