The Canine Health Foundation offers breed specific health articles, as well as an extensive list of articles on canine diseases. There is also a glossary of terms, information about health testing, and a good list of other canine health resources.
OFFA receives funds and offers grants for research into genetic diseases in animals. DNA test kits are available, information about what genetic diseases or conditions should be screened for in specific canine breeds, and offers articles on diseases. This site links to CHIC.