African horse sickness
African Horse Sickness (AHS) is a highly fatal and infectious disease, which affects horses, mules and donkeys. It is carried and spread by biting insects.
The disease is notifiable: if you suspect the disease, you must immediately notify the duty vet in your local Animal Health Veterinary Laboratories Agency (AHVLA) office.
The disease is not directly contagious between horses, has never occurred in the UK but is present (endemic) in sub-Saharan Africa. Dogs can also be severely infected by the virus, usually by eating infected horsemeat.
African Horse Sickness is presently endemic in large areas of sub-Saharan Africa. In the past it has been reported in North Africa and the Middle East, and was last reported in Europe in the 1980’s in Spain and Portugal. Zebras are reservoirs of disease and may be infected without showing clinical signs. Details of any changes in the situation can be found on the international disease monitoring web pages.
About the disease
AHS is caused by an orbivirus, and there are nine strains of the virus. Affected horses have a fever with laboured breathing, coughing and discharge from the nostrils. A less serious form can occur causing fever and swelling of the face.
Spread/transmission of disease
The spread of disease is influenced by climatic conditions which favour the spread of carrier insects (vectors) including warm, moist weather and high rainfall, as well as spread by wind dispersal. It is likely that the virus persists (overwinters) in other, unknown species in Africa when the insect is not active. This explains why the disease does not persist in other countries following an outbreak.
Housing horses in accommodation at times of peak midge activity will reduce the likelihood of midge attack but it is unlikely to fully protect your horse. A combination of protection measures is recommended to ensure the highest possible degree of protection is achieved. See:
Legislation and control strategy
Provisions for the control of African Horse Sickness are contained in the African Horse Sickness (England) Regulations 2012. The African Horse Sickness Control Strategy for Great Britain guides the reader through this legislation and equivalent legislation in Scotland and Wales, and outlines our control strategy for managing the disease.