Dear Doctor: The dog’s white hair is taking on a rust color
Q. My 12-year-old dog, Emmy, has been pure white her entire life — until the last 7 months. As you can see from the photo, she now has a rust-colored face and paws. Three different veterinarians have given me three different theories for why this has happened, ranging from old age to allergies. At this point she has been on four allergy medications, including steroids, but none of them has helped. I should note that she has also had pus in her left eye, which is red. I have been applying the over-the-counter eye ointment Maxitrol, but I am already on my fourth tube — it only works for a couple of days. Please help my baby girl. I don’t know what else to do.
Dear Ms. Hendershot,
A. Hair around a dog’s eyes may take on a rust color any time there is an increased flow of tears. Tears contain proteins that bind to iron, and when the tears reach the outside of the body and are hit by oxygen, they literally rust, explains Tufts veterinary ophthalmologist Stefano Pizzirani, DVM. It is particularly obvious on white-coated dogs.
Tear overflow can occur for a number of reasons. The most common is extra hairs rubbing onto the cornea, which is very sensitive. (Have you ever had a hair in your eye?) Sometimes an infection or foreign body causes a problem. Allergies, too, can increase tear production, with the rusty coloring showing up on the sides of the nose.
As for the rust color anywhere on the legs, including the paws, the cause is licking. Saliva, like tears, can cause a red stain. Common causes of excess licking include psychological triggers or again, allergies.
In the case of your own dog, Dr. Pizzirani says, it looks from the photo like there’s a small mass on the bottom of the dog’s left eye, at the edge of the eyelid. That can produce some friction on the cornea, he says, which would increase tearing and overflow.
The best bet would be to have Emmy examined and diagnosed by a veterinary ophthalmologist and perhaps a veterinary dermatologist. Proper treatment will bring her coat back to its natural color.