Equine Neuroaxonal Dystrophy and Degenerative Myeloencephalopathy

Area of Science:

• Veterinary Neurology
• Equine Genetics
• Animal Pathology

Background:

• Equine neuroaxonal dystrophy (eNAD) and equine degenerative myeloencephalopathy (EDM) are distinct pathological classifications of a similar neurodegenerative condition in horses.
• Both conditions manifest clinically with ataxia, often with an insidious onset during early development, but can also present later with behavioral changes.

Purpose of the Study:

• To summarize the current understanding of equine neuroaxonal dystrophy (eNAD) and equine degenerative myeloencephalopathy (EDM).
• To highlight the diagnostic criteria and potential genetic and environmental factors influencing these equine neurological disorders.

Main Methods:

• Histologic evaluation of the caudal medulla and cervicothoracic spinal cord is required for definitive diagnosis of eNAD/EDM.
• Review of existing evidence regarding the inheritance patterns and potential environmental modifiers of eNAD/EDM.

Main Results:

• eNAD and EDM are characterized by neuroaxonal degeneration in specific regions of the horse's central nervous system.
• Clinical presentation commonly includes ataxia, with variations in onset and additional signs like behavioral changes.
• Histopathology remains the gold standard for diagnosis.

Conclusions:

• eNAD/EDM are likely inherited equine neurological diseases.
• Vitamin E is implicated as an environmental factor that may modify the severity of the disease phenotype.
• Further research into genetic and nutritional factors is warranted for improved management and potential prevention strategies.