Why is my dog's hair stained under the eyes?
Introduction The staining of hair below the eyes of a dog, which is more prominent in white dogs, is referred to as Tear Staining. Tear stains are dark or reddish brown stains under a dog's eyes and they are caused by an overflow of tears. The discolouration comes from porphyrins which are iron-containing molecules produced when the body breaks down iron. Porphyrins are excreted through the gastrointestinal tract, urine, saliva, and TEARS! All dogs have some porphyrin in thei