Craniocervical junction abnormalities in dogs.

Craniocervical junction abnormality (CJA) is a term that encompasses a number of developmental anatomical aberrations at the region of the caudal occiput and first two cervical vertebrae. Chiari-like malformation appears to be the most common CJA encountered in dogs, and there has been a tremendous amount of clinical investigation into this disorder in recent years. Other abnormalities in this region include atlanto-occipital overlap, dorsal constriction at C1/C2 and atlantoaxial instability. This review article presents an overview of the current understanding of CJA in dogs, as well as medical and surgical treatment options available.