What Is Epiphora?

Epiphora is excessive tearing.
Epiphora, or tearing, is a common problem in brachycephalic (snub-nosed) breeds of dog. Excessive tearing can result from three mechanisms: obstruction to tear flow, eyelid dysfunction, and excessive tear production. A number of causative conditions may underlie each of these mechanisms. Normally tears are drained through the tear ducts, which are tube-like structures connecting the eyes to the nasopharynx (the back of the nose and throat). The tear ducts are part of the lacrimal system of each eye. Anything that obstructs these tear ducts anywhere along their course will cause epiphora. Congenital deformity of the tear ducts or failure of them to form holes (puncta) at the nasal end where tears drain into the nose will cause excess tearing. Swelling associated with inflammation and infection of the nose and sinuses may obstruct the tear ducts by compression. The tear ducts can also become clogged with mucus or pus. Foreign bodies may block tear duct openings and may also compress the ducts, as can tumors. Scar tissue, which may arise from an infection or trauma may obstruct the tear ducts also. If an affected dog’s tear ducts are physically obstructed with mucus, they can sometimes be flushed and the problem resolved. If the obstruction is caused by a tumor, scar tissue, foreign body, or congenital problem, flushing of the ducts may not work and surgery may be required. Unfortunately, there is no way to tell if flushing will work without actually trying to flush the ducts; anesthesia is required to do this. Excessive tearing may also occur when dysfunction or deformity of the eyelids prevents tears from reaching the tear ducts. Ectropion (the eyelid everts, or turns outward), entropion (the eyelid inverts, or turns inward), paralysis of the facial nerve, and eyelid scarring secondary to infection may result in epiphora. These conditions may require surgery. Overproduction of tears, where the produced tear volume exceeds the ability of the lacrimal system to drain them will result in epiphora. Overproduction usually is due to irritation to the eye. Entropion (permitting the eyelashes to curl in instead of curl out), eyelid tumors, inflammatory and infectious processes of the eyes and eyelids and congenital developmental anomalies of the eyelids will irritate the eye and produce excess tearing. Treatment is aimed at removing the source of the irritation. I encourage you to speak with your veterinarian about this problem and have your dog examined and treated. Your veterinarian may think that referral to a veterinary ophthalmologist is in order.