It is very common, in light-coated dogs, the appearance of brown or reddish spots under the eyes. They are due to an excess of humidity in the area, such as excessive tearing, which in turn occurs when the animal suffers some obstruction in the tear, allergies or other ophthalmological problems. All this causes a kind of "oxidation" that manifests itself through these signals.
All the tears of dogs are composed of several elements, among which we find iron and magnesium. When they come into contact with the air, these substances oxidize, creating a dark stain on our pet's hair. One of the consequences derived from all this is the appearance of fungi and bacteria, which greatly aggravate the problem. In the same way, if we clean this area with water we can also promote the appearance of this discoloration.
Sometimes this abundant tearing, also called ocular epiphora, is caused by a nutritional deficiency, so we should make sure that the feed that the dog eats is of high quality and provides it with the vitamins and minerals it needs. On other occasions, an allergic reaction is due to something that has been sniffed or ingested, or it is also possible that the tear duct is obstructed by some foreign body (as long as the problem manifests itself in only one eye). Therefore, it is best that the vet checks the animal's eyes to verify that there is no such problem and, if so, initiate appropriate treatment.
There are other factors that lead to the appearance of these spots. One of them is the race, Poodles and Chihuahuas being the most prone to suffer epiphora. This can be explained by the fact that the eye sockets of these dogs are excessively thin, which makes it difficult to contain tears. Age It is another detail to take into account, since the tears of the puppies are more acidic, which favors the reddish coloration, while the tear ducts of the elderly dogs tend to clog.
El excess fur in the area also favors tearing, as well as tap water. It contains too many minerals that facilitate the formation of stains, so it will be better to offer the animal bottled or filtered water.
On the Internet we find multiple Home Remedies to eliminate these annoying stains (saline, chamomile infusion, hydrogen peroxide ...), but it is best, as we said before, to go to the vet beforehand to make sure that our pet does not suffer from any ophthalmological problem and ask him to advise us which one the best remedy to end this problem.