Illegal horse imports into Britain lift risk of deadly disease

December 7, 2009

Horses illegally imported into Britain are increasing the risk of African Horse Sickness being introduced, a recent report says.

The report, commissioned by a government and industry group - the African Horse Sickness Working Group - believes an outbreak in Britain could halve the nation's equine industry and cost £3.5 billion.

Outbreaks have occurred twice in Europe during the 20th century, the most recent in Spain in 1990, probably linked to imports of infected zebras from Africa.

There are fears that global warming could increase the risk of the midge-borne disease reaching British shores.

However, the report also outlined risks around illegal equine imports.

"Although the risk of African Horse Sickness reaching the UK is currently officially stated as 'low'," the report said, "there are concerns about the increasing risk caused through the possibility of infected equines being illegally imported into the UK.

"The EC tripartite agreement, which allows horses to be moved between UK, France and Ireland, for breeding and production without an Intra-Trade Animal Health Certificate (ITAC) is also seen to contribute to the risk of the disease entering the UK."

The report says Britain has "an entirely susceptible horse population" and if midges became infected it could spread quickly.

"Vaccines are currently used against AHS in sub-Saharan Africa, where the disease is endemic and there is a stockpile available for potential use in the European Union, but these are currently considered to be an unattractive proposition for the UK, mainly because of the risk of the live vaccine reverting to virulence and spreading the disease.

"Slaughter of infected animals with movement controls and reduction of exposure to midges would currently be the main policy option to slow the spread of disease."

African horse sickness kills up to 90 per cent of infected horses within a week.

It is endemic in sub-Saharan Africa and has spread to Europe twice in the 20th century; the last outbreak was recorded in Spain in 1990.

It is spread principally by midges (Culicoides) of the same species that transmit bluetongue virus in cattle.

The spread of disease is influenced by climatic conditions which favour the survival of the vector insects, including warm, moist weather and high rainfall, as well as spread by wind dispersal.