shadow – Feb 4, 2011 12:00 AM

I was recently asked about Shadow's staining on the side of his mouth. This is a caused by a substance called Porphyrin (derived from the greek word for purple). Porphyrins are a group of naturally occurring organic compounds that are found in saliva, urine or on areas where moisture is present (between the pads). The presence of Porphyrin stains is related to an ongoing process of the breakdown of red blood cells in the body. This stain is visible on all the wolves here, but is more pronounced on the white arctic pelage. It is definitely more pronounced on Shadow than Malik, and may be related to an increased amount of salivation with Shadow's particular feeding habits. He does tend to wait until the wolf care staff get the chicken in the right size (his choice, not the staff), and this may stimulate more salivation.