Easily shed and exchanged, they could serve as a source of associative evidence if it could be established that different dogs of the same breed possess hair with sufficient variation of microscopic characteristics to permit some degree of individualization. Known dog hair samples were obtained from 25 pure bred German Shepherds who shared common lineage. Questioned hairs selected in the examiner's absence were compared macroscopically and microscopically to the known samples. Six of fifteen questioned hairs were correctly assigned to their sample of origin. No incorrect inclusions (Type II errors) occurred. The results of this preliminary study indicate that pure bred German Shepherd dogs possess some types of hair with sufficient variation of microscopic characteristics to permit some degree of individualization. (Publisher abstract)