Tear stains are a common issue among many light colored and toy dogs. The first step towards ridding your dog of tear stains is to pinpoint the cause. Once you know why your dog is getting tear stains, you can get rid of the problem, and clean the stains. The main cause of tear stains is excess tearing. The moisture as a result of excess tearing collects around the eye making it a prime location for the growth of bacteria and yeast. Most of the reddish-brown stains one sees on dog’s faces is due to ptyrosporin, or red yeast, learn more.