You may notice that some dogs, or maybe even your own dog, seems to have some brown stains or markings around their eyes. There is no need for immediate attention or alarm, but it is still important that you understand why this is happening.
The tears and saliva of a dog contain a metabolic by-product called porphyrin, which can react with sunlight and eventually cause a reddish color to appear in the hairs located around the eyes, or anywhere the dog may happen to lick. The reddening happens as a result of the hair shaft and groups of hairs in the same area will also appear to be affected.
If you would like to find a treatment for this problem in your dog, it is advised that you follow up with your veterinarian.