34th Annual Scientific Meeting proceedings

Objectives:

Atlanto-occipital (AO) luxation is uncommon in horses. Closed reduction has only been described postmortem in one horse. This case report discusses the successful treatment of a right latero-dorsal AO-luxation in a 17-month-old American Miniature Horse.  

Methods:

The colt was presented with a marked neck stiffness, hypometria of all four limbs and apparent swelling of the right atlas region. Radiographs confirmed the diagnosis of a right latero-dorsal AO-luxation. Furthermore, minor bleeding in the spinal cord was seen on MRI.  

Due to the mild clinical signs, it was decided to attempt a closed reduction of the luxation. The pony was positioned in left lateral recumbency. After unsuccessful attempts with the technique described by Barnes et al., the head of the pony was placed on the surgeon's right shoulder, while one hand was placed on each side of the atlas. An assistant pulled on the halter to hyperextend the AO-joint, while the surgeon guided the angle of the AO joint as well as manipulated the C1 manually. Crepitation was heard and felt, and radiographs confirmed successful reposition of the AO-joint. Hand-assisted recovery from anesthesia was uneventful. After the intervention, dexamethasone was administered for five days, followed by two days of meloxicam.

Results:

Immediately after recovery, the range of motion of the neck increased. The ataxia improved markedly in the following days. Five weeks later the horse returned to pasture without any clinical signs. 

Conclusions:

This report shows that closed reduction of an AO-joint luxation may be a viable treatment in horses with mild neurological signs.