The Chihuahua, as with all purebred breeds, has a higher risk than the general dog population of developing several serious conditions and diseases. Responsible, quality breeders work hard to lessen the risk of a puppy inheriting a genetically based disease; however, many conditions don't have a known hereditary factor at this time. Whether you've purchased your Chi from an outstanding breeder or not, it behooves all Chi owners to recognize the most serious diseases of the breed.