Signs and symptoms of tear stains in dogs
The most obvious sign of tear stains in light coloured dogs are the red marks in the hair below each eye.
These are much harder to see in darker coated dogs, and it may be that the damp hair from excessive tear production or the tears being drawn away from the eye into the fur are the easiest symptoms to see. There may be a discharge from the eye, depending on the cause of the tears, but this does not happen in every case.
If your dog has stains that are brown rather than red, particularly if there is a noticeable odour, then they may have a yeast infection that can be caused by the skin being constantly damp under the fur.