Ask the Vet: Probiotic May Reduce Dog's Tear Staining
Q: Cosette, my 5-year-old white toy poodle, has always had bronze staining beneath both eyes. Every year, her veterinarian examines her eyes and says they look fine, so I assume the bronze staining isn't a medical problem. What causes it, and what can I do about it?
A: Tear staining is the most common cause of bronze discoloration of the hair under the eyes of light-colored dogs. You are correct that it is not a medical problem but a cosmetic issue.
Tears contain porphyrins, substances that bind iron and darken to red-brown when exposed to light. When tears overflow the eyes, the porphyrins stain the fur.
Tears spill from the eyes for two reasons: 1) increased tear production due to eye pain, whether from hair irritating the eye, a corneal ulcer or some other problem; or 2) a blocked or malformed tear drainage system.
It sounds like Cosette's veterinarian has ruled out increased tear production, so her tear staining probably results from tears spilling over her eyelids rather than draining internally.
Normally, tears leave the eyes through the nasolacrimal duct system, draining through tiny holes at the lower inner corner of each eye and exiting through the nostrils. A conformational abnormality, from a covering over the tiny holes to a blockage of the duct as it travels to the nostrils, may be responsible for Cosette's tears spilling over her lower eyelids.
A veterinary ophthalmologist can advise you about whether flushing the nasolacrimal drainage system or corrective eye surgery will resolve the problem.
Or you can manage it by asking your groomer to keep Cosette's hair very short beneath her eyes so the hair doesn't trap her tears. Wash Cosette's face daily with a warm, damp cloth. Consider applying a bit of petroleum jelly to the hair below her eyes so her tears slide off.
Probiotics sometimes help prevent tear staining. Try an oral veterinary probiotic such as FortiFlora, Prostora or Proviable.
Don't give Cosette tylosin, tetracycline or any other antibiotic for her tear staining. Using antibiotics for cosmetic purposes may contribute to bacterial resistance and cause problems in the future.