Selected autoimmune diseases in the dog.
In summary, previous attempts to explain the role of inheritance in autoimmune disorders through family studies have been hampered by the variable degree of phenotypic expression. Our evidence utilizing dogs in family studies is consistent with the concept that genetic factors play some role in determining disease susceptibility. Recognizing the complexity of the genetic components involved in these studies, we have proposed a hypothesis of two classes of genes, one that relates to immunoregulation and another that specifies pathologic lesions (and thus the clinical signs). This dual system of interacting genes provides a rational explanation for many of the observations previously encountered in both human and canine studies.