http://www.aht.org.uk/news.html#msicut and pasted from the AHT website
"HELP US IDENTIFY MYSTERIOUS DOG KILLER
Since the beginning of August 2010, several dogs which have been walked on the Sandringham Estate, in Thetford Forest, in Clumber Park or Sherwood Forest have been taken seriously ill and currently vets and scientist are baffled by the cause.
The AHT has launched an investigation to try and find out the source of the illness which develops suddenly and causes vomiting, diarrhoea and lethargy. To enable us to learn more about the illness we need dog owners who have walked their dogs in any of the four sites to fill in a questionnaire - regardless of whether your dog was taken ill or not."
Further info on the website.