Hypoplasia of dens is a congenital non-formation of the pivot point of the second cervical vertebra, which leads to spinal cord damage."Hereditary and Congenital Diseases of Purebred Dogs." Retrieved from on 2007-03-13. Onset of the condition may occur at any age, producing signs ranging from neck pain to quadriplegia."Breed Predisposition to Disease and Congenital Conditions," Dr. Bob's All Creatures Site. Retrieved from http://www.petdoc.ws/BreedPre.htm on 2007-03-13. Hypoplasia of dens affects dogs. It is more commonly seen in certain breeds, including the Chihuahua, the Papillon, the Pointer and the Yorkshire Terrier.
