By Jennifer Coates, DVM
Eye discharge is a common problem in dogs. Some types are completely normal, while others are associated with potentially serious health concerns. In order to determine when professional help is necessary, pet parents need to understand the various types of dog eye discharge and what each may mean. Let’s take a look at five common types of dog eye discharge and what you should do about them.
1. A Little Goop or Crust
Tears play an essential role in maintaining eye health. They provide oxygen and nourishment to the cornea (the clear layer of tissue at the front of the eye) and help remove any debris that might get trapped there. Tears normally drain through ducts located at the inner corner of each eye, but sometimes a little bit of goop or crust will accumulate there. This material is made out of dried tears, oil, mucus, dead cells, dust, etc. It is most evident in the morning and is often perfectly normal. The goop or crust should be easy to remove with a warm damp cloth, the eyes should not be red, and your dog should not exhibit any signs of eye discomfort (rubbing, squinting, blinking, and sensitivity to light). The amount of “sleep” a dog produces each night (or after long naps) should stay relatively constant. If you notice any worsening of your dog’s condition, make an appointment with your veterinarian.
2. Clear and Watery
Excessive eye watering (epiphora) is associated with many different conditions that run the range from relatively benign to serious. Allergies, irritants, foreign material in the eye, anatomical abnormalities (e.g., prominent eyes or rolled in eyelids), blocked tear ducts, corneal wounds, and glaucoma (increased eye pressure) are common causes of epiphora in dogs.
If your dog has a relatively mild increase in tearing but his eyes look normal in all other respects and he doesn’t seem to be in any discomfort, it is reasonable to monitor the situation. Your dog may have simply received a face full of pollen or dust, and the increased tearing is working to solve the problem. But if the epiphora continues or your dog develops red, painful eyes or other types of eye discharge, make an appointment with your veterinarian.
3. Reddish Brown Tear Stains
Light colored dogs often develop a reddish brown discoloration to the fur below the inner corner of their eyes. This occurs because tears contain a pigment called porphyrin that turns this reddish brown color upon prolonged exposure to air. In the absence of other problems, tear staining in this area is normal and is just a cosmetic concern. If you want to minimize your dog’s tear stains, try one or more of these solutions: Wipe the area a few times a day with a cloth dampened in warm water or an eye cleaning solution; keep the fur around your dog’s eyes trimmed short; and/or add an antibiotic-free nutritional supplement that reduces tear staining to your dog’s diet.
Keep in mind that it can take several months for porphyrin stained fur to grow out and for the effects of any of these remedies to become obvious. If you notice an increase in the amount or a change in the quality of your dog’s tear staining or if your dog’s eyes become red and painful, make an appointment with your veterinarian for an eye examination.
4. White-Gray Mucus
Dry eye (keratoconjunctivitis sicca or KCS) is a condition that usually develops when a dog’s immune system attacks and destroys the glands that produce tears. With tear production being less than normal, the body tries to compensate by making more mucus to lubricate the eyes. But mucus can’t replace all the functions of tears, so the eyes become red and painful and may develop ulcers and abnormal corneal pigmentation. Left untreated, KCS can result in severe discomfort and blindness.
If you notice white-gray mucus collecting around your dog’s eyes, make an appointment with your veterinarian. He or she can perform a simple procedure called a Schirmer Tear Test to differentiate KCS from other diseases that are associated with increased eye mucus production. Most dogs respond well to treatment for KCS, which may involve cyclosporine, tacrolimus, artificial tears, and/or other medications. Surgery to redirect a duct carrying saliva from the mouth toward the surface of the eye can also be considered but should be reserved for those cases when medical treatment is unsuccessful.
5. Yellow or Green Eye Discharge
A dog whose eyes produce yellow or green discharge often has an eye infection, particularly if eye redness and discomfort are also evident. Eye infections can develop as a primary problem or as a result of another condition (corneal wounds, dry eye, etc.) that weakens the eye’s natural defenses against infection. Sometimes what looks to be an eye infection is actually a sign that a dog has a systemic illness or a problem affecting the respiratory tract, nervous system, or other part of the body.
Any dog who looks like he might have an eye infection should be seen by a veterinarian as quickly as possible.