The goal of the Canine Inherited Disorders Database (CIDD) is "to reduce the incidence of inherited disorders in dogs by providing information to owners and breeders, and to facilitate the best management possible of these conditions by providing current information to veterinarians."
The Inherited Diseases in Dogs (IDID) database is provided by the University of Cambridge Veterinary School.
The Online Mendelian Inheritance in Animals (OMIA) database is hosted by the National Institutes of Health and includes all animals, not just dogs. However, dogs are the best documented of all the animals found in the OMIA database.This database is considerably trickier to navigate than the other two unless you're already familiar with it.
Hopefully, you'll find these free online tools useful when you have questions or want to learn more about the health challenges of certain dog breeds.