Atlanto-axial stabilization for subluxation

Atlantoaxial instability (AA instability) is the term used to describe excessive movement between the C1 (atlas) and C2 (axis) vertebrae. The excessive movement can lead to spinal cord and/or nerve root compression causing pain and neurological dysfunction. Atlantoaxial instability can occur in any dog that suffers high-velocity blunt trauma, but most commonly occurs in small and toy breeds secondary to a congenitally malformed atlantoaxial joint. Signs include pain, difficulty walking, reduced head and neck movement, and respiratory distress. Chihuahua, Pekinese, toy poodles, Japanese chin, Pomeranian, Yorkshire terriers, Pekingese, and Maltese are particularly susceptible. Dogs can be severely affected requiring immediate treatment or may have mild signs that seem to come and go. Diagnosis is typically based on examination and diagnostic imaging (radiographs, CT, and/or MRI). Both medical and surgical treatments are available depending on the severity and chronicity of the problem. The neurology department at TAMU offers both medical and surgical treatment options for dogs diagnosed with AA instability.