African Horse Sickness

Isabel Wolf-Gillespie

In Africa we have our very own endemic equine disease – African Horse Sickness (AHS). AHS is a seriously real concern for every horse owner in most of Southern Africa and the disease affects them everyone directly or indirectly, regardless of whether AHS occurs in their area or not. Most horse owners that can afford to vaccinate are vaccinating their horses, however, impoverished rural communities in Africa most often don’t have the means to vaccinate their horses, mules or donkeys. Even in the very dry desert-like conditions of Africa, AHS occurs infrequently after heavy rainfall. AHS was first recorded in the Yemen in 1327 but the disease almost certainly originated in Africa. It was described by Father Monclaro, a monk, in a 1569 account of journeys into central and east Africa using Indian horses. In South Africa, AHS first appeared in horses that were brought to the Cape of Good Hope in 1652 by the Dutch East India Company. Sixty years after that was the first official, recorded outbreak in the Cape in 1719, in which 1700 horses died. Forty percent of the horse population was reported to have died in the worst season ever in 1854/ 55. Hundreds of years later, we still feel the devastation of this disease. The question about whether governments are doing enough to protect the African equine industry and whether it understands the value of the equine and its associated industries including the rural communities remains unanswered. 

The AHS virus caused over 1000 equine deaths in 2010/2011 resulting in a two-year suspension of all direct equine exports to the EU, costing the local industry an estimated US$150 million. The hacking, companion, traction, draught and transport function of equidae in all sectors of the African community cannot be quantified in monetary terms. The impact of AHS on the industry is devastating, and emotionally the cost is borne in the loss of a friend.

What is African Horse Sickness? African Horse Sickness is a highly infectious non-contagious, vector born viral disease affecting all species of Equidae. It is classified as an Orbivirus of the Reoviridae family of which there are nine serotypes. All serotypes (one to nine) are distributed throughout, although there is a variation in their temporal distribution. It occurs naturally on the African continent, and is characterized by respiratory and circulatory damage, accompanied by fever and loss of appetite.

Host and Vector Animals affected are, all breeds of horses (mortality rate of 70-90%), mules and donkeys. Wild life Equine species (Zebras) are resistant to the disease. The vector host, Culicoides midge, spreads AHS virus.

How do horses contract the disease? AHS does not spread directly from one horse to another, but is transmitted by the Culicoides midge, which becomes infected when feeding on other infected equidae. It occurs mostly in the warm, rainy season when midges are plentiful, and disappears after frost, when the midges die. Most animals become infected in the period associated with sunset and sunrise, when the midges are most active.

Symptoms The disease manifests in three ways, namely the lung form, the heart form and the mixed form.

- The lung (dunkop) form is characterized in the following manner: very high fever (up to 41° C); difficulty in breathing, with mouth open and head hanging down; frothy discharge may pour from the nose; sudden onset of death; very high death rate (90%).
- The heart (dikkop) form is characterized in the following manner: fever, followed by swelling of the head and eyes; in severe cases, the entire head swells (“dikkop”); loss of ability to swallow and possible colic symptoms may occur; terminal signs include bleeding (of pinpoint size) in the membranes of the mouth and eyes; slower onset of death, occurring four to eight days after the fever has started; lower death rate (50%).
- The mixed form is characterized by symptoms of both the dunkop and dikkop forms of the disease.

(Information supplied by the University of KwaZulu Natal and the African Horse Sickness Trust)

In the former Transkei of South Africa for example, equids form an integral part of life for the AmaXhosa people. Their role is to fetch water and wood, be a mode of transport, plow land and herd livestock and give employment opportunities. Equids as a mode of transport, are an environmentally friendly way of travelling, a quality needed in today’s world that should be supported and encouraged. Together with my husband Lloyd, I have been running an outreach project focusing on the social and economic upliftment of the AmaXhosa people. The animal owners often lack the necessary skills and resources, which results in serious abuse and neglect of the animals.

A few years ago we had to move from the former Transkei and our project area has shifted since then to Botswana. It’s a challenge to maintain and grow the project which is funded by ourselves mostly and currently includes AHS vaccinations, internal and external parasite control, wound care, education, and youth and skills development.

If you are keen to get involved please get in touch This email address is being protected from spambots. You need JavaScript enabled to view it..




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