John Craven: Can we prevent horse sickness?

Climate change and globalisation encourage the spread of an African disease.

Gloucestershire floods


When the midges start biting this summer, they will simply be a nuisance to most of us out and about in the countryside. But to anxious farmers they could be bearers of diseases that kill their livestock. And now there’s concern for horse lovers as well.

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African horse sickness (AHS) rapidly and painfully destroys more than 90 percent of infected animals. For centuries it has been endemic in sub-Saharan Africa and should it ever reach our shores it could devastate our equine industry, which is worth £7bn a year.

Until recently, it was seen as a remote threat but climate change and globalisation have changed that – plus the fact that AHS is spread by the same type of midge that brought the animal disease bluetongue from Africa five years ago. The insects arrived, maybe in a consignment of flowers to the Netherlands, during Europe’s hottest summer since records began – so they survived.

Midge mayhem
Now another midge-born disease, Schmallenberg, which causes dreadful deformities in lambs and calves, has brought great sadness this year to several hundred UK farms. It’s named after a picturesque town in central Germany (which was previously best-known for making socks) where the first cases were reported.

The midges somehow got to Schmallenberg from the African continent and quickly moved across Northern Europe. During last autumn’s heatwave, they began biting sheep and cattle in the early stages of pregnancy – with appalling results. So, is a pattern developing – midges, hot weather, rapid transport – that could open the door to AHS in our horse-loving nation?

The financial and emotional impact would, of course, be enormous in a country with around 1.4 million horses and more than 70,000 people employed full-time to look after them.

A report by the AHS Working Group, led by the charity The Horse Trust, predicted that a widespread outbreak could wipe out half the UK equine industry “with irreparable damage caused to racing and major setbacks to the various sporting disciplines, such as three-day eventing, show jumping and dressage.”

Defra is stepping up its guard and working on new regulations to control any outbreak. EU rules already demand the slaughter of all infected horses and any others they have been in contact with, together with protection zones within a 60-mile radius of infected premises. But the truth is that no one knows whether AHS will strike.

In the battle zone
Professor Peter Mertens, of the Institute for Animal Health, which studies infectious diseases in farm animals, tells me: “The risk is in the unknown and in some ways we are in a battle zone. AHS is a real concern and we, among others, are taking the threat seriously and working on a vaccine.

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“Neither bluetongue nor Schmallenberg was expected and it’s my guess that, within five years, something else will turn up. Whether it will affect animals or humans, or both, who knows? Just one infected insect can cause an outbreak, and to combat this new type of danger we need vigilance, good surveillance, control strategies, effective vaccines and continued investment in research.” Not to mention a large dose of luck.