Autoimmune diseases

This is a group of diseases that is caused by a failure of the immune system. It includes sebaceous adenitis, pemphigus, and VKH (skin diseases); hemolytic anemia; systemic lupus; polyarthritis; and some thyroid disease.

Although these diseases seem to be genetic, they are often triggered by stress. Some seem to be specific to a few breeds, while others affect many breeds. Little is known about the mode of inheritance; that is, whether they are simple as progressive retinal atrophy and sebaceous adenitis are in some breeds or are, like hip dysplasia, a complex association of many genes.

Environmental influence is suspected in the onset of some autoimmune problems, but research is slow in proving a definite link.