For the gene nerds, this one is also interesting. It's about poodles.
If you want to really get into some reading here's all the studies: http://www.cgejournal.org/contentWe demonstrated that the incidence of both Addison’s disease and sebaceous adenitis in Standard Poodles increased as a result of an artificial genetic bottleneck involving a small group of show-winning founders from the mid-twentieth century. This bottleneck led to inbreeding over two decades with the results that 50–60 % of an average Standard Poodles ancestry can be traced to a few lines. We conclude that a number of ancestral traits associated with autoimmunity, some common to both SA and AD and some unique to each, were concentrated by inadvertent positive selection during close linebreeding for show winning form.