Equine neuroaxonal dystrophy (NAD) is a neurological condition in younger horses, frequently of the quarter horse breed. Symptoms include symmetrical ataxia, abnormal base-wide stance at rest, and proprioceptive deficits in the limbs. Vitamin E deficiency may contribute to disease severity.
NAD is very similar to equine degenerative myeloencephalopathy (EDM)
. The only different between the two conditions is the location of axonal degeneration within the central nervous system. Postmortem examination is currently the only method to definitely diagnosis NAD or EDM. NAD and EDM both appear to be caused by genetics.