Equine disease events resulting from international horse movements: Systematic review and lessons learned

An analysis of the factors leading to equine disease events was used to support the development of international recommendations for mitigating the risk of disease dissemination through sport horse movements (high health, high performance - 'HHP' horses).

A review was undertaken to identify the factors resulting in equine disease events following international movement of horses to draw lessons in support of the development of international recommendations for the safe movements of a specific subpopulation of horses: the HHP sport horses.

Systematic review carried out in accordance with the PRISMA statement.

The review covered disease events that occurred from 1995 to 2014, identified from the databases of the World Organisation for Animal Health (OIE) and international surveillance reports.

Overall, 54 disease events were identified, of which 7 were contained in post arrival quarantine and the others resulted in the introduction of pathogens into importing countries. For 81% of the introductions, the OIE recommendations applicable to the diseases involved had not been complied with. Subclinical infections are a challenge for international trade: 88% of the regulated movements that resulted in introductions involved infected horses that showed no clinical signs at the time of import. Biosecurity and management practices in resident equine populations were identified as important mitigating factors in preventing disease spread to the local horse population.

The global increase in international horse movements, if not appropriately regulated and supervised by competent veterinary authorities and respective equine industry partners, could potentially lead to increased global spread of infectious equine diseases. Appropriate mitigation measures and compliance with OIE import recommendations for specific diseases can significantly reduce this risk. The recommendations proposed under the HHP approach take into account the mitigation measures identified by this review as important factors in preventing pathogen introduction and spread.