Equine herpesvirus type 1 myeloencephalopathy (EHM) is the most severe complication associated with EHV-1 infection and represents a major health and economic concern for the equine industry. Sport horses are frequently involved in EHV-1 outbreaks due to factors inherent to competition, including transportation, stress, and the commingling of horses from different geographical origins. However, little information is available regarding their long-term functional outcome and their true ability to return to competition following recovery from the disease.
Historically, the development of neurological signs has been associated with a poor athletic prognosis and has often been considered the end of the affected horse’s sporting career. Nevertheless, recent advances derived from the investigation of natural outbreaks have helped clarify the factors influencing functional recovery and return to exercise. Available evidence indicates that a substantial proportion of horses surviving the acute phase of EHM can resume athletic activity and may even regain athletic performance levels comparable to those achieved before infection. However, the likelihood of complete recovery appears to depend on several clinical factors, including the severity of the initial neurological impairment, the development of systemic complications, and the magnitude of the inflammatory response triggered during the disease.
This review brings together, for the first time, the available evidence regarding functional and athletic recovery in sport horses affected by EHM, analyses the clinical variables associated with long-term prognosis, and provides practical recommendations for owner counselling and the planning of a progressive return-to-exercise program. Beyond survival, understanding which horses are likely to regain their competitive performance represents an essential tool for clinical decision-making and for establishing realistic expectations throughout the recovery process.
