Owners of little white dogs know all too well the scourge of tear staining, those red-brown streaks in the fur that run from the inside corners of the eyes and down alongside the nose. (Little black dogs have just as much tear staining but on the dark background isn’t very visible.) Rarely is there any sort of physical problem associated with it, but it is unsightly and for many owners it would be nice to have a clean white face to look at. The questions I usually get are: why does it happen and how can you make it go away?
Small breed dogs are prone to several anatomical tendencies that result in epiphora--the technical term for the spilling of tears over the lower eyelid. Normally extra tears are collected into a tiny duct that opens in the inside corner of the eyelid. Sometimes, in small breed dogs in particular, the inside corner of the lower eyelid rolls inward ever so slightly, causing the opening of the duct to be smashed closed enough that it doesn’t collect tears effectively. Small breeds also frequently have hair growing in the inside corner of the eye that can touch the surface of the eye. The hairs don’t seem to cause discomfort, but the contact to the surface of the eye stimulates increased tear production which can overwhelm a possibly already ineffective tear collection system If excess tears don’t get collected into the ducts they end up spilling over the edge of the lower eyelid and wicking down the fur along the nose. Inside the tears is a reddish pigment called porphyrin that, when piled layer upon layer will start to become visible, especially against a white background.
One approach to stop epiphora and staining is to surgically alter the factors in the eyelid that lead to tear spillage. Errant hairs that touch the eye can be frozen off and the shape of the corner of the eye can be altered. Normally I would reserve these somewhat invasive procedures for dogs that are having a clinical problem as a result of their tear spillage rather than just a cosmetic issue.
There are numerous wipes and potions available to try to bleach out the pigment in the hairs. Some contain chemicals like hydrogen peroxide that make me nervous when used around the surface of the eye, so don‘t just assume it is safe because it was available to buy. Some people have success using a small toothbrush to streak a little petroleum jelly or white petrolatum on the affected area of hair in order to waterproof it and avoid the staining.
A very common remedy is a product called Angel’s Eyes. It is given as a tasty treat and its active ingredient is tylosin, an antibiotic. Nobody knows exactly how tylosin keeps tears (and saliva) from staining fur, but the leading theories are that it binds chemically with the porphyrins so that they are not secreted in tears or saliva, and that it also may alter some bacterial populations in the wet fur that contribute to discoloration. It is logical to be concerned about long term low grade antibiotic use for cosmetic problems in dogs, but there isn’t much evidence that Angel’s Eyes causes problems. The antiboitics tetracycline and doxycyclene have similar anti-staining properties as well. On the Veterinary Information Network I also found suggestions for using powdered buttermilk in the food and dried parsley as well. Nobody even tries to venture a guess as to the mechanism of action of either of those two ingredients. It sounds improbable to me, but there are people out there that swear by it, and I certainly can’t think of any reason that either buttermilk or parsley could cause harm. Any oral medication or supplement will only prevent staining of fur, so the hairs that are already present and stained when treatment begins will have to fall out before the improvement can be seen.
The easiest approach for dealing with tear staining is to learn to ignore it or perhaps even to consider it an integral part of your dog’s coloration. Perfectionists everywhere are probably gasping an clutching their chests as I speak, but really there is really almost never any physical reason to have to do anything about tear staining at all.