Q. I have a cat that has a problem with a weeping eye (at the nose), a condition she has had for several years.
Now, the iris is gradually turning orange, starting at the nose, and the eye is starting to squint slightly. This seems to be getting worse. When the cat was adopted at about nine months old, she already had this condition (she was microchipped, but we received no response from her former owner).
Our veterinarian has tried several different medications to no avail. Do you have any advice?
A. Dear Sean: There are many reasons for a runny eye, but the long duration suggests to me a benign cause. My first suspicion is a plugged tear duct. Tears are the normal lubricant that prevents friction when blinking, and are constantly produced by glands adjacent to the eye.
Tear fluid drains from the eye through a small duct located on the inner aspect of the eyelid. The signs of a plugged tear duct include clear discharge, most noticeable from the inner aspect of the eye, adjacent to the nose. Because a plugged duct cannot be detected by inspection alone, its presence must be considered and specifically tested.
The simplest test to detect the patency of the tear duct is to place a drop of ophthalmic fluorescent dye (sterile and non-harmful) into each eye. In the normal cat, dye will be detected in the nostrils (tears drain into the nose; that’s why you get a runny nose when you cry). If dye is detected only in one nostril, and not the side with the tearing, this suggests a blocked tear duct. And plugged tear ducts can be re-opened with a minor surgical procedure (best performed by a board-certified veterinary ophthalmologist).
So you may ultimately need to request referral to an ophthalmologist for evaluation. They will likely be able to resolve the problem.
Michael Stone DVM, ACVIM
Clinical Assistant Professor
Cummings School of Veterinary
Medicine at Tufts University