Epiphora (Excessive Tearing) in Dogs
Dr. Noelle McNabb
Obstruction of tear flow through the nasolacrimal duct system
Veterinary care often includes diagnostic tests to determine what is causing the epiphora or ocular discharge. Epiphora is initially classified into one of three categories:
Reflex stimulation of tears due to ocular irritation
Overproduction of tears by the lacrimal glands (least common)
Once a specific diagnosis has been established, appropriate treatment can be instituted.
There are several potential diagnostic tests. Your cat may be referred to a veterinary ophthalmologist for further evaluation and completion of some of these tests, which may include:
Complete ophthalmic examination including a magnified examination of the eyelids, tear drainage holes (puncta), conjunctiva, cornea and front chamber of the eye
Schirmer tear test to determine if tear production is below normal, normal or excessive
Fluorescein and possibly Rose Bengal staining of the cornea to assess for the presence of ulcers, lacerations or scratches
Tonometry to measure the pressure within the eye to evaluate for the presence of glaucoma
Flushing of the tear duct system with saline to determine if it is open all the way to the nose
Dacryocystorhinography is the flushing of the entire tear duct system with a contrast agent that is visible on X-rays. It is a special X-ray technique that helps outline the tear drainage system from the corner of the eye all the way to the nose. This X-ray study may be done when congenital absence of part or all of the nasolacrimal system is suspected, or when compression, cystic dilatation, scarring or obstruction of the system is suspected. It is performed under general anesthesia.
The goals of treating epiphora include 1) eliminating any causes of excessive tearing, 2) eliminating any obstruction to tear flow (if possible), 3) decreasing the irritation caused by the tears themselves, and 4) keeping the face and area around the eye dry and clean. Specific treatment depends on the cause of the epiphora or ocular discharge. There is no general nonspecific treatment for epiphora.
Treatment of Eye and Orbital Disorders_
Once the underlying eye condition is diagnosed, appropriate therapy is started for that condition. As the underlying problem improves, the epiphora also gradually subsides.
Some deformities of the eyelids, eye lashes and facial hairs require corrective surgery in order to eliminate the irritation and the epiphora.
Topical medications that cause epiphora are usually stopped and replaced with a less irritating medication.
Infections may require both topical and oral medications.
Some forms of blockage of the tear duct system are not correctable and the epiphora can be expected to be chronic.
Managements of Chronic Epiphora
When the cause of the epiphora cannot be corrected, or corrective measures fail to resolve the tearing completely, then a daily maintenance routine may be necessary to decrease the adverse effects of the epiphora.
The area around the eye, especially towards the nose, is washed and dried each day using a gentle cloth and lukewarm water.
Topical eye antibiotics and/or anti-inflammatory medications may be needed periodically to decrease irritation caused by the epiphora.
Oral tetracycline therapy may be used for short periods of time to reduce severe tear staining of the hair around the eyes and face. Tetracycline is an antibiotic that concentrates in the tear glands and chemically changes some of the components of the tears. As a result they are less irritating to the skin and cause less staining. Oral tetracycline should not be use long-term in dogs because it may cause liver disease. It is also not recommended in animals less than seven months of age, as it will cause yellow discoloration of the developing permanent teeth.
Oral tylosin may also decrease tear staining and can be used for longer periods of time than oral tetracycline. Tylosin is an antibiotic that comes in a powder form and is usually administered on the food.
Recommendations for home care depend upon the underlying cause of the problem. In addition, some general care is necessary to maintain the health of the eye.
Gently clean away any eye discharge with a sanitary cloth or tissue, and keep the area clean and dry until the cause of the problem is identified.
Do not delay in bringing your pet to a veterinarian for examination as some causes of epiphora, especially those sudden in onset, are potentially vision threatening and require immediate medical or surgical attention.