Battle against Grass Sickness to be centred in Dubai

A worldwide research project to find the cause of Equine Grass Sickness, which killed Dubai Millennium, is to be coordinated in Dubai. For over 90 years, scientists have been baffled by the illness. But Dr Ulrich Wernery, Scientific Director of the Central Veterinary Research Laboratory, believes the cause will be found within five years.

Wernery has been given the task of finding out what causes Equine Grass Sickness by General Sheikh Mohammed bin Rashid Al Maktoum, Crown Prince of Dubai and UAE Defence Minister. "When this horse died, Sheikh Mohammed said to me 'Ulie, please do something. We must try to find out what is the cause and try to get all the people involved together'," Wernery said.

However, he warned the search for the cause would not be easy. "It is a complicated problem, which is why the cause has not been found until now." Possible causes include poisonous plants, chemicals, bacteria, insects, fungal toxins and a form of botulism called Clostridium botulinum. A further complication is that it is believed the weather and grass temperatures play a part since the majority of cases occur between April and June in the UK.

Work has already begun at the Central Veterinary Research Laboratory on grass and soil samples taken from the Dalham Hall stud farm owned by Sheikh Mohammed where Dubai Millennium was stabled and died.

The next step will be to bring together various groups and individuals conducting research into Equine Grass Sickness at a meeting in Dubai later this month to discuss the way forward. "It is incredible that the cause of the disease has not been found. It is high time to do that," Wernery said. "We can fly to the moon but we can't find the toxin in the blood? That's impossible.

"I am quite sure we will find the cause very soon. With our technology and medicine we should achieve this goal quickly." Wernery described his role as one of coordinating the research, although he said he would carry out some research of his own at the Central Veterinary Research Laboratory.

"When we meet we will decide what to do. Most probably we will agree that one institute will work on one aspect of the problem and another on a different aspect. "One institute or group of people cannot solve the problem. It has to be a combined effort."

Dubai Millennium, described by Sheikh Mohammed as the best horse he has owned, died a week after being fed freshly cut grass from a meadow at the stud farm. The horse underwent three operations in an effort to save his life but according to Wernery the damage done to the horse's autonomic nervous system meant that he was unlikely to survive.

"From the information I saw it was clear that all of Dubai Millennium's nerve endings in the gut had been destroyed," Dr Wernery said. "From what I saw, it was obvious the horse would not survive but we hoped for a miracle."

Wernery said that Dubai Millennium had fought hard to survive. "He did not eat for a week and had to be fed via a drip. In the end he could not cope with the disease because his whole intestine did not work at all."

Wernery said that the operations which Dubai Millennium underwent were intended to clean out his intestine. But, he added, this was not possible given the fact that his intestine was 20 metres long. "At the end I think he died from the toxins produced by rotten food in his intestine," Wernery said.

Great Britain has the highest incidence of Equine Grass Sickness in the world. It was first diagnosed in 1907 at an army camp in Montrose, Scotland, when 100 horses died. Today around 200 horses a year die from Equine Grass Sickness in the UK.

Initial research into the problem suggested that the clinical symptoms of Grass Sickness resembled botulism. In 1920, investigations began on the assumption that Bacillus botulinus, now known as Clostridium botulinum, was the cause. But in 1927 a medical journal reported that there was no association between Equine Grass Sickness and botulism.

However, Wernery thinks that there is a link. Without ruling out other possible causes, Wernery has his own theory about what causes Equine Grass Sickness. "My theory is that the spores of this particular bacteria are ingested. They can survive in the soil for hundreds of years and maybe they are transported in the faecal droppings of birds. Therefore, only one small part of the meadow is contaminated.

"These spores then germinate in the stomach or intestine of the horse and create the toxin that kills the nerve endings." Wernery also believes there may be a genetic link, which would explain why some horses are more likely to suffer from Equine Grass Sickness than others.

One immediate focus of investigation will be the fertiliser used on the grazing pastures at the farm. Wernery said he had been told the stud used a compost made from rotting plants and household waste. He added that research done in Germany had found traces of botulism in rotting household waste.

Wernery said Equine Grass Sickness had only been identified at the Dalham Hall stud farm three times since 1996, despite the fact that hundreds of horses have grazed on the farm's pastures. He said it was just bad luck that Dubai Millennium had contracted the disease.

He described Dubai Millennium's death as a tragedy. But, he added, something good could come from it if the cause for Equine Grass Sickness was found. In that case, he said, Dubai Millennium would have a lasting memorial and the grateful thanks of horse owners and breeders the world over.