Equine neuroaxonal dystrophy/degenerative myeloencephalopathy in Gypsy Vanner horses.
Authors: Powers Alexis, Peek Simon F, Reed Steve, Donnelly Callum G, Tinkler Stacey, Gasper David, Woolard Kevin D, Finno Carrie J
Journal: Journal of veterinary internal medicine
Summary
# Equine Neuroaxial Dystrophy/Degenerative Myeloencephalopathy in Gypsy Vanner Horses Equine neuroaxial dystrophy/degenerative myeloencephalopathy (eNAD/EDM) is a progressive neurodegenerative condition linked to vitamin E deficiency in genetically susceptible young horses, but had never been formally documented in Gypsy Vanner horses until this work. Researchers examined 26 Californian Gypsy Vanners and 4 cases from the Midwest presenting with neurological signs suspicious for eNAD/EDM, measuring blood vitamin E concentrations before and after a 28-day supplementation protocol (10 IU/kg RRR-alpha-tocopherol daily), whilst confirming diagnosis through necropsy in four affected animals. Remarkably, 94% of Californian horses tested had dangerously low pre-supplementation vitamin E levels (≤2.0 µg/mL), yet even after supplementation only 52% achieved normal concentrations (≥3.0 µg/mL), with younger horses showing particularly poor response to treatment. Necropsy confirmed eNAD/EDM pathology in all four euthanased cases, establishing this breed as susceptible to the condition for the first time. Given these findings, veterinarians working with Gypsy Vanners should screen young stock for vitamin E status and consider prophylactic supplementation as part of breed-specific herd health protocols, though practitioners should be aware that supplementation response may be inconsistent and requires serial monitoring rather than assumption of correction.
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Practical Takeaways
- •Screen young Gypsy Vanner horses for vitamin E deficiency, particularly those with neurologic signs, as the breed appears to have genetic predisposition to eNAD/EDM
- •Standard vitamin E supplementation protocols (10 IU/kg daily) may be insufficient for Gypsy Vanners; monitor blood concentrations post-supplementation rather than assuming adequate repletion
- •Consider aggressive vitamin E supplementation and nutritional management in young Gypsy Vanners as a preventive measure given the high prevalence of deficiency and associated neurodegenerative risk
Key Findings
- •94% (16/17) of Gypsy Vanner horses from California had pre-supplementation blood vitamin E concentrations ≤2.0 μg/mL
- •Only 52% (12/23) of supplemented horses achieved normal vitamin E concentrations (≥3.0 μg/mL) despite 28 days of oral supplementation at 10 IU/kg
- •eNAD/EDM was confirmed at necropsy in 4 euthanized Gypsy Vanner horses with clinical neurologic disease
- •Normalization of vitamin E status was significantly associated with increasing age (P = 0.02)