## Overview Atlas-axis dysfunction encompasses abnormal movement or pain at the articulation between the first and second cervical vertebrae. Because the majority of cervical axial rotation occurs at this joint, dysfunction commonly produces resistance to lateral bending of the head (“shaking the head no”) and may contribute to performance problems or asymmetric gaits. Causes range from mild osteoarthritis to ligamentous injury or subluxation. ## Causes Repetitive stress, trauma, osteoarthritis, and compensatory changes from lower cervical or forelimb pain are typical. True instability is uncommon but serious. ## Diagnosis Motion palpation, observation of head carriage, and ridden evaluation identify the dysfunction. Radiographs assess for osteoarthritis or malalignment; advanced imaging is reserved for cases with neurologic signs or suspected instability. ## Treatment Anti-inflammatory medication, joint injection when osteoarthritis is confirmed, manual therapies, and rehabilitation exercises form the core of management. Surgical stabilization is rarely indicated. ## Recovery and Prognosis Most horses with mild to moderate dysfunction return to full work with appropriate therapy. Cases with significant instability or advanced degenerative change have a more guarded outlook. ## Prevention Balanced training, attention to dental and bit issues, and early treatment of neck discomfort help maintain normal atlas-axis function.
resistance to lateral head movement; asymmetric neck posture; reduced performance in lateral work; pain on palpation of the atlas-axis region
## Overview Atlas-axis dysfunction encompasses abnormal movement or pain at the articulation between the first and second cervical vertebrae. Because the majority of cervical axial rotation occurs at this joint, dysfunction commonly produces resistance to lateral bending of the head (“shaking the head no”) and may contribute to performance problems or asymmetric gaits. Causes range from mild osteoarthritis to ligamentous injury or subluxation. ## Causes Repetitive stress, trauma, osteoarthritis, and compensatory changes from lower cervical or forelimb pain are typical. True instability is uncommon but serious. ## Diagnosis Motion palpation, observation of head carriage, and ridden evaluation identify the dysfunction. Radiographs assess for osteoarthritis or malalignment; advanced imaging is reserved for cases with neurologic signs or suspected instability. ## Treatment Anti-inflammatory medication, joint injection when osteoarthritis is confirmed, manual therapies, and rehabilitation exercises form the core of management. Surgical stabilization is rarely indicated. ## Recovery and Prognosis Most horses with mild to moderate dysfunction return to full work with appropriate therapy. Cases with significant instability or advanced degenerative change have a more guarded outlook. ## Prevention Balanced training, attention to dental and bit issues, and early treatment of neck discomfort help maintain normal atlas-axis function.
resistance to lateral head movement; asymmetric neck posture; reduced performance in lateral work; pain on palpation of the atlas-axis region