Understanding equine motor neuron disease — a vitamin E deficiency condition causing progressive muscle weakness.
Equine motor neuron disease causes significant welfare impairment through progressive neuromuscular weakness. Affected horses show characteristic signs — low head carriage, frequent weight shifting between limbs (to relieve muscle fatigue), abnormal sweating, and rapid loss of muscle mass particularly over the topline and hindquarters. The muscle weakness causes poor coordination and difficulty maintaining normal postures.
The welfare of horses with EMND depends critically on the stage at which supplementation is initiated. Horses treated early in the disease course — before irreversible neuronal damage — may stabilise and show significant functional improvement. Those with advanced neurodegeneration continue to decline despite supplementation as the damaged neurons cannot regenerate.
Prevention is straightforward: adequate vitamin E intake from fresh pasture or supplementation. Horses without daily pasture access require vitamin E supplementation — natural vitamin E (d-alpha-tocopherol) is significantly more bioavailable than synthetic forms. Regular monitoring of vitamin E status in stabled horses prevents deficiency from developing silently.